* Fix long line errors in abci, crypto, and libs packages

* Fix long lines in p2p and rpc packages

* Fix long lines in abci, state, and tools packages

* Fix long lines in behaviour and blockchain packages

* Fix long lines in cmd and config packages

* Begin fixing long lines in consensus package

* Finish fixing long lines in consensus package

* Add lll exclusion for lines containing URLs

* Fix long lines in crypto package

* Fix long lines in evidence package

* Fix long lines in mempool and node packages

* Fix long lines in libs package

* Fix long lines in lite package

* Fix new long line in node package

* Fix long lines in p2p package

* Ignore gocritic warning

* Fix long lines in privval package

* Fix long lines in rpc package

* Fix long lines in scripts package

* Fix long lines in state package

* Fix long lines in tools package

* Fix long lines in types package

* Enable lll linter

* Pin range scope vars

* Don't disable scopelint

This PR repairs linter errors seen when running the following commands:
golangci-lint run --no-config --disable-all=true --enable=scopelint

Contributes to #3262

* make sure we create valid private keys:

 - genPrivKey samples and rejects invalid fieldelems (like libsecp256k1)
 - GenPrivKeySecp256k1 uses `(sha(secret) mod (n − 1)) + 1`
 - fix typo, rename test file: s/secpk256k1/secp256k1/

* Update crypto/secp256k1/secp256k1.go

* switch from fork (tendermint/btcd) to orig package (btcsuite/btcd); also

 - remove obsolete check in test `size != -1` is always true
 - WIP as the serialization still needs to be wrapped

* WIP: wrap signature & privkey, pubkey needs to be wrapped as well

* wrap pubkey too

* use "github.com/ethereum/go-ethereum/crypto/secp256k1" if cgo is
available, else use "github.com/btcsuite/btcd/btcec" and take care of
lower-S when verifying

Annoyingly, had to disable pruning when importing
github.com/ethereum/go-ethereum/ :-/

* update comment

* update comment

* emulate signature_nocgo.go for additional benchmarks:
592bf6a59c/crypto/signature_nocgo.go (L60-L76)

* use our format (r || s) in lower-s form when in the non-cgo case

* remove comment about using the C library directly

* vendor github.com/btcsuite/btcd too

* Add test for the !cgo case

* update changelog pending

Closes #3162 #3163
Refs #1958, #2091, tendermint/btcd#1

* crypto/secp256k1: Fix signature malleability, adopt more efficient encoding

This removes signature malleability per ADR 14, and makes secp match
the encoding in ADR 15.

* (squash this) add lock

Signatures are now []byte, which saves on the number of bytes after
amino encoding

(squash this) address Ismail's comment

* crypto/secp256k1: Add godocs, remove indirection in privkeys

The following was previously done for creating secp256k1 private keys:

First obtain privkey bytes. Then create a private key in the
underlying library, with scalar exponent equal to privKeyBytes.
(The method called was secp256k1.PrivKeyFromBytes,
fb90c334df/btcec/privkey.go (L21))

Then the private key was serialized using the underlying library, which just
returns back the bytes that comprised the scalar exponent, but padded to be
exactly 32 bytes.
fb90c334df/btcec/privkey.go (L70)

Thus the entire indirection of calling the underlying library can be avoided
by just ensuring that we pass in a 32 byte value. A test case has even be written
to show this more clearly in review.

* crypto/secp256k1: Address PR comments

Squash this commit

* crypto: Remove note about re-registering amino paths when unnecessary.

This commit should be squashed.

Currently the top level directory contains basically all of the code
for the crypto package. This PR moves the crypto code into submodules
in a similar manner to what `golang/x/crypto` does. This improves code
organization.

Ref discussion: https://github.com/tendermint/tendermint/pull/1966

Closes #1956

This reverts commit d02c5d1e30.