move channel commands into subpackage
add autojoin and nodelete admin-only channel settings
add createdAt and lastJoinedAt timestamps for channel expiry
add commands to set autojoin and nodelete
add config file with default channels and expiry settings
add permission based linkifying/color codes
add channel list command
add /chat set pmnotification command
Merge pull request #11 from andrepl/master

IT'S BEDTIME!