make e_alert WBOD work in X11 even when built with wayland support
make e_alert WBOD work in X11 even when built with wayland support

If enlightenment is built with support for wayland, then previously
the WBOD would not work if we were running the same binary with X11.
This was because the alert system would try to connect via drm by
default (due to wayland build option). We fix that by checking for the
existance of $DISPLAY (as this will not be present under drm), and
running the X11 codepath if it is found, running the drm codepath if
it is not found.

Signed-off-by: Chris Michael <2c9adca9bdb4861297f022d161a6a7c2d4597bd5@osg.samsung.com>

tasn/enlightenment,rvandegrift/e,rvandegrift/e,rvandegrift/e,tasn/enlightenment,tasn/enlightenment