Remove header files from spec build target

This generated a warning, unsure why these were added in the first place.
Rename MessageParsingSpec
Start implementing parsing outside IRCBroker

Added tests for behavior, this needs a good clean refactoring
though. Removing GLGIRCMessages as much as possible and just
using a protocol to communicate between the parser and the
broker might be a good step in the right direction.
Delete example spec

Thought this happened a while ago but maybe that was only on a branch.
More tests for message parsing behavior