Ownership of decoration textures is moved from SceneOpenGL::Window to
OpenGLPaintRedirector. The PaintRedirector is responsible for updating
the textures whenever they change. For this GLTexture is extended by an
update(QImage, QPoint) method which uses glTexSubImage2D to update only
the changed parts.
The big advantage compared to before is that if e.g. only a button is
animated only the button part is updated instead of the complete deco
part.
This patch changes the behavior of strictly bound textures such that
they are only updated if the corresponding window has been damaged.
Additionally GLTexture now keeps track of the current filter and
wrapmode setting.
REVIEW: 103655
Additionally:
- hide the GLTexture implementation using dpointers
- drop the unused function SceneOpenGL::Texture::optimizeBindDamage()
- Texture::load now loads a new texture and does not update the existing one
REVIEW: 101999
