Add functions to retrieve some of the properties of the screen used by
the backend, like its dimensions (also physical, in millimeters); the
number of screens. Also add setters and getters for the double click
time (in milliseconds) and distance.
* clutter/clutter-backend.c: Clear the event queue when
disposing the backend object; remove the initialisation
of the backend structure members...
* clutter/glx/clutter-backend-glx.c: ... and keep it here
in the backends where it belongs.
* clutter/clutter-private.h: Remove inclusion of backend-specific
headers; update the main context object; add the declarations for
the event queue functions.
* clutter/clutter-backend.[ch]: Add the abstract ClutterBackend
object, which holds backend-specific settings, the main stage,
and the event queue. Every backend must implement a subclass of
ClutterBackend and ClutterStage.
* clutter/clutter-feature.c: Protect the GLX specific calls
behing #ifdef HAVE_CLUTTER_GLX.
* clutter/clutter-actor.c:
* clutter/clutter-group.c:
* clutter/clutter-clone-texture.c: Include GL/gl.h
* clutter/clutter-event.[ch]: Update public API and implement the
event queue private API; hold a reference on the event objects;
move out the keysym-to-unicode table; add the new event types.
* clutter/clutter-color.h: Include clutter-fixed.h
* clutter/clutter-main.c: Update API; get the main stage
from the backend object; process the event received from the
queue; lock/unlock the main mutex if we have one; move the
initialisation process sooner in the init sequence, in order to
have the backend object when we check for options; call the
backed vfuncs in the pre/post parse hooks.
* clutter/clutter-stage.c: Make ClutterStage and abstract class,
implemented by the backends.
* clutter/clutter/glx/clutter-glx.h:
* clutter/clutter/glx/clutter-backend-glx.[ch]:
* clutter/clutter/glx/clutter-event-glx.c:
* clutter/clutter/glx/clutter-stage-glx.[ch]:
* clutter/clutter/glx/Makefile.am: Add the GLX backend.
* clutter/clutter/egl/clutter-backend-egl.[ch]:
* clutter/clutter/egl/clutter-event-egl.c:
* clutter/clutter/egl/clutter-stage-egl.[ch]:
* clutter/clutter/egl/Makefile.am: Add the stub for a EGL backend.
* examples/*.c: Update for the new API.
