Fixed some docstrings.

Added code to the groupchat method that picks up the command 'list commands'.

Added message body normalization to the groupchat parser.

Signed-off-by: The Doctor <drwho@virtadpt.net>
Added a check in the groupchat parser to only run commands in a MUC that are
specifically addressed to a particular bot.

Signed-off-by: The Doctor <drwho@virtadpt.net>