The BTextBox used for sending messages has been moved from the main
window to individual ConversationViews, allowing seperate histories,
texts, etc., to exist in different conversations.
EditingFilter (a filter that hooked into MainWindow) was previously used
to field special key combos with this textbox, including "ENTER" for
sending, but this has been replaced with a new textview subclass
(SendTextView).
Jaidyn Ann