If the user has permission to change a room's subject or name, they can
now edit the text views displaying them (toward the top of the window).
When enter is pressed, the changes will be sent to the protocol.
To do this, a BTextView subclass was added to libinterface
(splitting somewhat from SendTextView)― EnterTextView sends a message
containing the text to the given target when the user hits enter sans
modifiers.
89ff195c8d