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.
Replaces libinterface's ToolButton, a custom button that can display
a pop-up menu on click (along with a custom image). It didn't scale well
with different themes and font-sizes compared to BButtons― which
ToolButton is supposed to look like to begin with.
A BButton-derived class is used instead, so these buttons look more
in-place among other buttons.
Jaidyn Ann