Fix executing minecraft server commands from IRC.

The dispatchCommand() method is not thread safe, and therefore should be
wrapped in a runnable and dispatched from a synchronized task. As well,
before, executing a command did not use getCommandSender(), instead
parsing the IRC nickname into a CommandSender, which causes problems if
your IRC nick is not the same as your ingame nick.

I also removed Eclipse specific files and added them to the gitignore,
as they aren't required for compilation and only clutter the required
code

I've only tested this code with an InspirIRCd link, and it works perfectly. It should for standalone as well, just haven't tested that yet.