alter conf_grab(_kbd) to first ungrab AnyKey/AnyModifier, then proceed
to grab keys in keybindingq.  we don't need to ungrab/grab on every
addition to the queue, just once with a complete keybindingq; simplify
grabbing keys per screen (during init) and during a MappingNotify.

while here, change conf_grab_{kbd,mouse} to require only a Window.
fix type in a ClientMessage (xu_sendmsg).
Unlike other parse.y variants, cwm's allowed 'command xx /path/to/xx' without
quotes. Reinstate this support lost in recent sync diff and add a comment to
show that it's intentional. ok okan@
Check for, and honour, CWStackMode and CWSibling change requests during a
ConfigureRequest event.  Additionally, honour a border width change;
detailed report and patch from Mike Small.
move synthetic responses and have client_msg only work with WM_PROTOCOLS,
since that's all ClientMessageEvent is for anyway.
allow mouse button4 and button5; from Rodrigo Mosconi
now that we have conf_screen, which configures individual screens
*after* config parsing, we no longer need to split up display/screen
initialization, so collapse.
move Cursors into conf.
when selfont is configured, make sure we continue and configure the rest
of the screen (quick fix); discovered the hard way by Rodrigo Mosconi.
properly fix (and re-organize) selfont selection.