Fixes NerdNu/NerdBugs#117

Fixes NerdNu/NerdBugs#117

1. Clanchat Owner can no longer leave if the channel has members (he can if its empty, however)

2. /clanchat <whatever here>, if not a valid command, will now print out the help message instead of stating "Command Not Found"

3. /c #channel, /cm #channel, and /cm members channel will no longer work if you are not a member of said channel. (Implemented /cm and /clanchat members because of S, I'd rather not let people know who I'm talking to if it involves certain events)

4. Updated text for /clanchat (/cm now properly explains what it does)

Thanks!