* 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.