Test revoking old commitment tx

[contrun]

This PR adds a unit test to check that we can revoke an older commitment transaction.

While developing on this PR, I found a few bugs in current implementation.

• There is an incompatibility between the way of hashing commitment lock witnesses in cfn-node and cfn-scripts. https://github.com/nervosnetwork/cfn-node/issues/129
• The current way of deriving revocation public key is wrong. We can't obtain the correct private key when the counterparty reveals his revocation secret.
• We are skipping one commitment point while sending and verifying RevokeAndAck messages.
• The commitment transaction outputs should use both the revocation key and delayed output key of the same party.

I also made one change that is required to construct the revocation transaction.

• Save remote commitment numbers whenever a new local commitment transaction is committed · Issue #132 · nervosnetwork/cfn-node