#112 enh: right click on channel and check join on start

[Jerry Haltom]

Enchancement Request:

A user should be able to right click on a channel tab
and choose "Join on Startup", which would check or
uncheck the menu item. Status of the menu item would be
loaded from the "Join Channels" text box in the Server
List. The auto joining of the server itself would be
smart to unautojoin when the channels are empty.