modified to use casting everywhere.

this resulted in blocking on the tcp:recv call; so when a topic change occurs,
- twitter bot is notified
- irc bot recv's and blocks
- twitter bot responds, this call is queued
- twitter bot crashes due to timeout
- irc bot recv call completes (ie someone says something, or ping)
- twitter bot response is processed

this should be resolved if the irc tcp:recv functionality is moved into its own gen_server:
- listen server starts up, opens the port, begins blocking on recv
- talk server starts up, allows posting to irc without waiting for the blocked recv call to complete
- twitter server starts up

listen server hears a topic change, informs twitter server, goes back to listening.
twitter server posts a status update and informs talk server, goes back to whatever gen_servers do in their spare time.
talk server posts into irc, resumes gen_server leisure activity
split irc server into listen and talk servers