This caused stack overflow panics in E2E tests, e.g.:

```
2020-11-24T02:37:17.6085640Z validator04    | runtime: goroutine stack exceeds 1000000000-byte limit
2020-11-24T02:37:17.6087818Z validator04    | runtime: sp=0xc0234b23c0 stack=[0xc0234b2000, 0xc0434b2000]
2020-11-24T02:37:17.6088920Z validator04    | fatal error: stack overflow
2020-11-24T02:37:17.6089776Z validator04    |
2020-11-24T02:37:17.6090569Z validator04    | runtime stack:
2020-11-24T02:37:17.6091677Z validator04    | runtime.throw(0x12dc476, 0xe)
2020-11-24T02:37:17.6093123Z validator04    | 	/usr/local/go/src/runtime/panic.go:1116 +0x72
2020-11-24T02:37:17.6094320Z validator04    | runtime.newstack()
2020-11-24T02:37:17.6095374Z validator04    | 	/usr/local/go/src/runtime/stack.go:1067 +0x78d
2020-11-24T02:37:17.6096381Z validator04    | runtime.morestack()
2020-11-24T02:37:17.6097657Z validator04    | 	/usr/local/go/src/runtime/asm_amd64.s:449 +0x8f
2020-11-24T02:37:17.6098505Z validator04    |
2020-11-24T02:37:17.6099328Z validator04    | goroutine 88 [running]:
2020-11-24T02:37:17.6100470Z validator04    | runtime.heapBitsSetType(0xc009565380, 0x20, 0x18, 0x1137e00)
2020-11-24T02:37:17.6101961Z validator04    | 	/usr/local/go/src/runtime/mbitmap.go:911 +0xaa5 fp=0xc0234b23d0 sp=0xc0234b23c8 pc=0x432625
2020-11-24T02:37:17.6103906Z validator04    | runtime.mallocgc(0x20, 0x1137e00, 0x117b601, 0x11e9240)
2020-11-24T02:37:17.6105179Z validator04    | 	/usr/local/go/src/runtime/malloc.go:1090 +0x5a5 fp=0xc0234b2470 sp=0xc0234b23d0 pc=0x428b25
2020-11-24T02:37:17.6106540Z validator04    | runtime.convTslice(0xc002743710, 0x21, 0x21, 0xc0234b24e8)
2020-11-24T02:37:17.6107861Z validator04    | 	/usr/local/go/src/runtime/iface.go:385 +0x59 fp=0xc0234b24a0 sp=0xc0234b2470 pc=0x426379
2020-11-24T02:37:17.6109315Z validator04    | github.com/tendermint/tendermint/crypto/secp256k1.PubKey.String(...)
2020-11-24T02:37:17.6151692Z validator04    | 	/src/tendermint/crypto/secp256k1/secp256k1.go:161
2020-11-24T02:37:17.6153872Z validator04    | github.com/tendermint/tendermint/crypto/secp256k1.(*PubKey).String(0xc009565360, 0x11e9240, 0xc009565360)
2020-11-24T02:37:17.6157421Z validator04    | 	<autogenerated>:1 +0x65 fp=0xc0234b24f8 sp=0xc0234b24a0 pc=0x656965
2020-11-24T02:37:17.6159134Z validator04    | fmt.(*pp).handleMethods(0xc00956c680, 0x58, 0xc0234b2801)
2020-11-24T02:37:17.6161462Z validator04    | 	/usr/local/go/src/fmt/print.go:630 +0x30a fp=0xc0234b2768 sp=0xc0234b24f8 pc=0x518b8a
[...]
2020-11-24T02:37:17.6649685Z validator04    | 	/usr/local/go/src/fmt/print.go:630 +0x30a fp=0xc0234b7f48 sp=0xc0234b7cd8 pc=0x518b8a
2020-11-24T02:37:17.6651177Z validator04    | created by github.com/tendermint/tendermint/node.startStateSync
2020-11-24T02:37:17.6652521Z validator04    | 	/src/tendermint/node/node.go:587 +0x150

```

"Squashes" the changelog from RCs 2-6 into one changelog message for 0.34.0, and adds the changelog pending.

…l based on it (#5638)

Partially closes #5550

also, since multiple StopPeerForError calls may be executed in parallel,
only execute StopPeerForError once

Closes #5541

make response values non nullable in privval

Does this need a changelog for master?

Closes: #5581

cc @tarcieri

Fixes #5422. That turned out to be a whole lot easier than expected.

Backport of #5536.

Before: scheduler receives psBlockProcessed event, but does not mark block as processed because peer timed out (or was removed for other reasons) and all associated blocks were rescheduled.

After: scheduler receives psBlockProcessed event and marks block as processed in any case (even if peer who provided this block errors).

Closes #5387

When a peer is stopped due to some network issue, the Reactor calls scheduler#handleRemovePeer, which removes the peer from the scheduler. BUT the peer stays in the processor, which sometimes could lead to "duplicate block enqueued by processor" panic WHEN the same block is requested by the scheduler again from a different peer. The solution is to return scPeerError, which will be propagated to the processor. The processor will clean up the blocks associated with the peer in purgePeer.

Closes #5513, #5517

Fixes #5439. This is really a workaround for #5519 (unless we require async implementations to return ordered responses, but that kind of defeats the purpose of having an async API).

Fixes #5511.

Fixes #5371.

Required for #5291 to set timeouts for remote signers.

Required for #5291, to generate configuration files with state sync RPC servers.

Reduces the state sync discovery time from 20 to 15 seconds, and makes it configurable.

This caused the node to crash whenever any state sync-related request was called via the ABCI UNIX socket client.

Clean up some inconsistent formatting and missing PR numbers.

Closes #625

Fixes #5377 and comments in #4588 (review).

Closes #5145

also applies to light/client

evidence: modify evidence types (#5342)

light: detect light client attacks (#5344)

evidence: refactor evidence pool (#5345)

abci: application evidence prepared by evidence pool (#5354)

## Description

Make an interface for the state store. 

Closes: #5213

## Description

Check block protocol version in header validate basic. 

I tried searching for where we check the P2P protocol version but was unable to find it. When we check compatibility with a node we check we both have the same block protocol and are on the same network, but we do not check if we are on the same P2P protocol. It makes sense if there is a handshake change because we would not be able to establish a secure connection, but a p2p protocol version bump may be because of a p2p message change, which would go unnoticed until that message is sent over the wire.  Is this purposeful?

Closes: #4790

This reverts the "fix" in #5311, after the real fix in #5328.

Fixes #5328.

## Description

remove unneeded types 

![](https://media1.giphy.com/media/fSAyceY3BCgtiQGnJs/giphy.gif)

ref #5288

On startup, the peer-to-peer stack may have peers connected before the state sync process begins, causing these to not trigger `AddPeer` events and thus not be used for snapshot discovery. Broadcasting a snapshot request to these explicitly makes sure we discover snapshots from existing peers as well.

## Description

remove lunaticEvidence

## Description

Remove ConflictingHeaders & compositeEvidence types


Ref #5288

## Description

Allow dialing of private and unconditional peers through the RPC

Closes: #1705

* config: rename prof_laddr to pprof_laddr and move it to rpc

also, remove `/unsafe_start_cpu_profiler`, `/unsafe_stop_cpu_profiler`
and `/unsafe_write_heap_profile` in favor of pprof server functionality.

Closes #5303

* update changelog

* log start

State sync broke in #5231 since the genesis state is not propagated explicitly from `NewNode()` to `Node.OnStart()` and further into the state sync initialization. This is a hack until we can clean up the node startup process.

Implementation spec of Double Signing Risk Reduction [ADR-51](https://github.com/tendermint/tendermint/blob/master/docs/architecture/adr-051-double-signing-risk-reduction.md) by B-Harvest
- Add `DoubleSignCheckHeight` config variable to ConsensusConfig for "How many blocks looks back to check existence of the node's consensus votes when before joining consensus"
- Add `consensus.double_sign_check_height` to `config.toml` and `tendermint node` as flag for set `DoubleSignCheckHeight`
- Set default `consensus.double_sign_check_height` to `0`  ( it could be adjustable in this PR, disable when 0  )

Refs

- [ADR-51](https://github.com/tendermint/tendermint/blob/master/docs/architecture/adr-051-double-signing-risk-reduction.md)
- [https://github.com/tendermint/tendermint/issues/4059](https://github.com/tendermint/tendermint/issues/4059)
- [https://github.com/tendermint/tendermint/pull/4262](https://github.com/tendermint/tendermint/pull/4262)

## Description

Verify only +2/3 of the commit. 

Closes: #5259

## Description

Remove secp256k1 as discussed in the tendermint dev call. The implementation has been moved to the [Cosmos-SDK](443e0c1f89/crypto/keys/secp256k1)

Closes: #XXX

## Description

Add chainid to requests to privval. This is a non-breaking change and hardware devices can opt to ignore the field.
 
Closes: #4503 

Took the approach of passing chainID to the client instead of modifying `GetPubKey` because it would lead to a larger change throughout the codebase and in some places it could get tricky to get chainID.