Separate the signed response from the unsigned ones.

Trying to keep this within the same class is like calling out for
problems with response trickery and a messy code. The Signed response
code is really just the same as for the non-signed, but looking for data
in the better places. Also implementing the ->getData() call getting the
signed data from the response. This should be used always really here.
Fix bad default for method and dig up method from payload unless we have it.
Namespace wrong.
Whitespace.