include/protocol: Remove headers that don't correspond to a current protocol module
modules/sporksircd: Remove SporksIRCD protocol module

SporksIRCD was abandoned by Elizacat, and she has approved
the removal of this module.  There are currently no known
networks running SporksIRCD.
Merge pull request #332 from lstarnes1024/master+removeoldproto

Remove unused protocol headers and remove SporksIRCD support (2nd attempt)