gallium: remove st_context_iface and other stuff, remove indirections, rename and clean up the rest in the "st" interface
This simplifies the state tracker interface that we have between st/mesa and the DRI/WGL/GLX frontends.
The DRI/WGL/GLX frontends can call st_context functions directly. There is no need for this abstraction anymore because GL is now the only user of those frontends (previously it was also OpenVG).
A lot of cruft and complicated indirections are removed, and the remaining structures are given new names that are more self-explanatory.
The terms such as st_framebuffer_iface
and st_manager
are completely abolished in the interface and the DRI/WGL/GLX frontends. They actually meant dri_drawable
and dri_screen
. The base structures are given new names: pipe_frontend_drawable
and pipe_frontend_screen
. The individuals frontends specialize them for DRI, WGL, GLX, etc. This also renames "iface" to "drawable" in st/mesa etc., making it easier to read and clarifying what it actually meant.