The current code relied on some widget to cause a redraw when the focus changes.
Obviously, this assumption is wrong.
Instead, the code now uses the proper "focus" and "unfocus" signals for setting
titlebar colors, but it also needs to set these colors when a new titlebar is
created (v1 of this patch forgot that). For this reason, update_colors has to be
saved for when a titlebar's colors are updated.
This commit also reverts the ugly redraw_hook hack from commit a1918b8306.
Signed-off-by: Uli Schlachter <psychon@znc.in>
e24c09e828