Pass binary abis to sign function

[randytorres]

The binary abi is being passed to the sign function, the function is not doing anything with the abi right now.

[chris-allnutt]

@randytorres looks like this needs a conflict resolution

[brandonfancher]

@randytorres This looks good. We'll need to update a few consumers of this API down the line, but that can be done when we cut a new npm release, and the changes should be fairly straightforward. So I approve going ahead and merging after conflict resolution.