This introduces -DWLR_USE_UNSTABLE and adds information regarding the
stability status to all headers. I started with a conservative set of
headers to mark as stable:
- types/wlr_matrix.h
- util/edges.h
- util/log.h
- util/region.h
- xcursor.h
It was broken because the damage extents were rotated about its
own center, not about the center of the surface.
This adds a new wlr_region_rotated_bounds that rotates regions.
This allows us to have only one code path (for both non-rotated
views and rotated views) and optimizes rendering for rotated
views.
