Split IRC message if they are long.

IRC has a 512 byte maximum message size that includes the privmsg and
destination data. Use textwrap at 400 characters to approximate proper
splitting of long IRC messages to avoid exceptions that occur when
sending more than 512 bytes.

Change-Id: I575ce3694f4b399a3adf5432f6f6971307d9e202
Merge "Split IRC message if they are long."