Merge pull request #6 from Splinti/master

Fixed setting of the comment
Merge pull request #7 from Splinti/master

Fixed formatting of the info-comment
Enable seek - buffer_before_play in mpd.conf must not be 100% in order for seek to work ...
Listen only to private messages
cleanup
added ability to change crossfade
code cleanup, bugfixes
added link to documentation to the #help text
Allow to seek backwards :)
Use user_id = -1 for unregistered users to reflect the Mumble protocol
display filename if there are not id3 tags