Implemented JOIN

Implemented and documented JOIN in accordance  to the RFC 2812 specifications, and added test cases similar to the examples in the specifications.
Implemented Kick and cleaned up Join

Implemented kick according to the specifications and simplified join a bit, as some of the map extractions were a bit more explicit than needed.
Implemented from kill to list.
Merge branch 'master' into join-to-list

Conflicts:
	test/clojirc/commands_test.clj
Simplified expressions for links and list commands.

As per emiln's suggestion, needless use of match has been removed a couple of places.
Redid helper-function to take simplification into account.
Merge pull request #21 from emiln/join-to-list

Implement JOIN to LIST commands