framebuffer: Don't mark the clip dirty at mid scene

https://bugzilla.gnome.org/show_bug.cgi?id=712562
framebuffer: Fix clip tracking in the unclipped case

Leaving the clip bounds untouched means that it will retain the stale value
of whatever it was when we last had a clip; reset it so that it contains the
full framebuffer contents instead.

https://bugzilla.gnome.org/show_bug.cgi?id=712562
cogl-texture-2d: Add update_area equivalent for Wayland
Revert "framebuffer: Fix clip tracking in the unclipped case"

This broke gnome-shell's StScrollViewFade.

This reverts commit 5c5715f4dab19a8f36015413a20ff64ceff59b09.
Revert "framebuffer: Don't mark the clip dirty at mid scene"

This patch doesn't look right because now nothing will ever set
clear_clip_dirty = TRUE. Presumably that would mean that if a
rectangle is drawn and then the journal is flushed before the
framebuffer is read, then it would think it could return the clear
color even though it shouldn't.

Perhaps a better approach would be to make a second version of
_cogl_framebuffer_mark_mid_scene that doesn't set the clear_clip_dirty
flag and call that from the journal instead. As this patch was pushed
without review and without first going into the master branch I think
it makes sense to just revert it and apply a new version to master.

This reverts commit 3eb63f67a34420b30ef812a1610aa9e9a80a93a3.
Declare interface types as void and remove cast macros

This declares the interface types CoglFramebuffer, CoglBuffer,
CoglTexture, CoglMetaTexture and CoglPrimitiveTexture as void when
including the public cogl.h header so that users don't have to use lots
of C type casts between instance types and interface types.

This also removes all of the COGL_XYZ() type cast macros since they do
nothing more than compile time type casting but it's less readable if
you haven't seen that coding pattern before.

Unlike with gobject based apis that use per-type macros for casting and
performing runtime type checking we instead prefer to do our runtime
type checking internally within the front-end public apis when objects
are passed into Cogl. This greatly reduces the verbosity for users of
the api and may help reduce the chance of excessive runtime type
checking that can sometimes be a problem.

(cherry picked from commit 248a76f5eac7e5ae4fb45208577f9a55360812a7)

Since we can't break the 1.x api this version of the patch actually
defines compatible NOP macros within deprecated/cogl-type-casts.h