compositor: Make sure surface->transform.matrix,inverse are always valid
compositor: Make sure surface->transform.matrix,inverse are always valid

First step towards getting rid of the transform.enabled optimization.

sir-murray/weston,udoprog/weston,giucam/weston,eyolfson/weston,Fantu/compositor-spice,kwm81/weston,Fantu/compositor-spice,Tarnyko/weston-xdg_surface_present,jonnylamb/weston,mchalupa/weston,udoprog/weston,krezovic/weston,eyolfson/weston,xorgy/weston,Fantu/compositor-spice,jonnylamb/weston,Tarnyko/weston-xdg_surface_present,Gnurou/weston,giucam/weston,mchalupa/weston,Gnurou/weston,kwm81/weston,xorgy/weston,sir-murray/weston,krezovic/weston