The broadway backend would move the focus from one window to another based on
where the mouse was (i.e. 'focus-follows-mouse' approach). Handling the focus
this wait didn't play well with widgets which rely on focus-in-event and
focus-out-event, like the GtkEntry when using a completion popup window, see
e.g:
https://bugzilla.gnome.org/show_bug.cgi?id=708984
So instead, setup broadway to require a click in a window to move the focus
(i.e. 'click-to-focus' approach):
* The implicit GDK_FOCUS_CHANGE events that were generated upon reception of
BROADWAY_EVENT_ENTER or BROADWAY_EVENT_LEAVE are removed.
* The broadway daemon will now keep track of which is the focused window
* Whenever the daemon detects an incoming BROADWAY_EVENT_BUTTON_PRESS, it will
trigger the focused window switch, which sends a new BROADWAY_EVENT_FOCUS to
the client, specifying which windows holds the focus.
* Upon reception of a BROADWAY_EVENT_FOCUS, the client will generate a new
GDK_FOCUS_CHANGE.
* gdk_broadway_window_focus() was also implemented, which now requests the
focus to the broadway server using a new BROADWAY_REQUEST_FOCUS_WINDOW.
This is based on an initial patch from Aleksander Morgado <aleksander@lanedo.com>.
With this we always roundtrip position change to the webbrowser.
This avoids conflicts when things change from both directions (app and user).
Also, we fake configure evens when there is no web client to ensure
apps get the events.
