* Don't use pointer receivers for PubKeyMultisigThreshold

* test that showcases panic when PubKeyMultisigThreshold are used in sdk:

 - deserialization will fail in `readInfo` which tries to read a
 `crypto.PubKey` into a `localInfo` (called by
  cosmos-sdk/client/keys.GetKeyInfo)

* Update changelog

* Rename routeTable to nameTable, multisig key is no longer a pointer

* sed -i 's/PubKeyAminoRoute/PubKeyAminoName/g' `grep -lrw PubKeyAminoRoute .`

upon Jae's request

* AminoRoutes -> AminoNames

* sed -e 's/PrivKeyAminoRoute/PrivKeyAminoName/g'

* Update crypto/encoding/amino/amino.go

Co-Authored-By: alessio <quadrispro@ubuntu.com>

* crypto: revert to mainline Go crypto lib

We used to use a fork for a modified bcrypt so we could pass our own
randomness but this was largely unecessary, unused, and a burden.
So now we just use the mainline Go crypto lib.

* changelog

* fix tests

* version and changelog

* tmhash is fully 32 bytes. closes #1990

* AddressSize

* fix tests

* fix max sizes

Closes #2001

* ed25519: use golang/x/crypto fork

* changelog

* gix GenerateFromPassword

* fixes from review

* crypto: Remove unnecessary ed25519 and secp256k1 prefixes from amino routes.

* (squash this) add changelog

* (squash this) multisig amino fixes

* (squash this) fix build error

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

(squash this) address Ismail's comment

* crypto: Add benchmarking code for signature schemes

This does a slight refactor for the key generation code. It now calls a
seperate unexported method to allow generation from a reader. I think this
will actually reduce time in generation, due to no longer initializing an
extra slice. This was needed in order to enable benchmarking.

This uses an internal package for the benchmarking code, so that this can
be standardized without being exported in the public API. The benchmarking
code is derived from agl/ed25519's benchmarking code, and has copied the
license over.

Closes #1984

The privkey.Generate method here was a custom-made method for deriving
a private key from another private key. This function is currently
not used anywhere in our codebase, and has not been reviewed enough
that it would be secure to use. This removes that method. We should
adopt the official ed25519 HD derivation once that has been standardized,
in order to fulfill this need.

closes #2000

* 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.

This commit updates the godocs for the package, and adds an optimization
to the privkey.Pubkey() method.

The optimization is that in golang, the private key (due to interface
compatibility reasons) has a copy of the public key stored inside of it.
Therefore if this copy has already been computed, there is no need to
recompute it.

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