Merge pull request #273 from Morphan1/master

Update to 1.6.2
Allow colons in Narrate and Announce text.
Fix kill and item drop listeners.
Fix Invisible command. Allow it to be used on players.
Make Sign command attach signs to surfaces.
Fix other listeners.
Add debug to Shoot command.
Make world events not trigger twice for special items.
Make 'on player chats' determinations work