Chatwindow keyboard focus regression

[diptongo@…]

In 0.11.1, if chatwindow is focused, whatever key press is sent to the input textbox (at the bottom), even if that textbox does not have focus (e.g. the messages textarea has been clicked). In 0.11.2 keyboard focus is only transferred from textarea to textbox if the pressed key is enter; other key presses are lost.

If click to focus is used in the WM configuration it is always easier to click the textarea, as it is larger, and the start writing.

[asterix]

(In [8900]) [Davidov] use gtk.AccelGroup? to handle key press. Fixes #1503. also fixes #3466