Add initial support with Packet class

This commit introduces a new file `ircpacket.py` which will allow probot
to parse messages from the IRC server from `socket` and interpret them
into what they actually mean. In the future, packets will be subclasses,
but right now this is code that is just a barebones implementation.
Add preliminary support for threading

This commit adds more support for threading in `probot.py` and
`irctools.py`. `probot` will act as the main thread for the program,
sending and receiving messages from the server. `irctools` will be a
second thread which parses messages from the server, processes them for
appropriate commands, and returns the appropriate message to send via
`pipe()` back to the main thread.