Thanks to Michael Stapelberg, there is now a xcb-only port of libXcursor which
does everything we need. This patch switches awesome over to that new library.
Since the only reason for using XOpenDisplay() instead of xcb_connect() was so
that we can use libXcursor, we can get back to that older state again. This
means that this effectively reverts the following commits:
531f8b415c "Added initial support for Xlib cursor themes"
77243cd09a "Add x11-xcb to the pkg-config checks"
779d43fc46 "Don't let Xlib own the event queue"
03759b4847 "Fix keyboard layouts"
Signed-off-by: Uli Schlachter <psychon@znc.in>