Plugin improvements and Chivalry parser fix

This pull request carries the following improvements:

* Event mapping method moved from Plugin class to Parser class: I think it's better to have all the code stored in the same function since the event mapping can take place only if an event is being registered thus it's useless to have a separate method.
* Added some basic test cases for event registering (with hook mapping and without)
* Added a fix to the `chiv.py` module which patches the AdminPlugin at runtime, modifying `doList()`and `cmd_find()`methods so they display the client database id together with the name instead of the client slot number (Unreal Engine 3 relies on the client GUID to perform actions like Kick, Ban, and this can be retrieved from the database, thus executing `!kick @1234 reason` will work perfectly). More info: http://forum.bigbrotherbot.net/general-discussion/!list-command