Emulator

Though there are quite a few GL_REPORT_ERROR() and -D() 'calls' in Dolphin,
there are way too few for it to be useful. Many OpenGL calls aren't
followed by a call to GL_REPORT_ERROR, which causes the one at for instance
TextureMngr.cpp (line 477) to attract almost all of the actual errors. Note
the comment there about Super Mario Sunshine; the same is true for various
parts of Metroid Prime (especially with water-like structures, such as the
poisoned water before Flaahgra or the lava in the Magmoor Caverns).

I noticed this became a problem when I tried to fix issue 493, where I
changed the behaviour of SetScissorRect() and added a GL_REPORT_ERROR just
to be sure. The errors that were attracted by TextureMngr.cpp before were
now often completely taken over by Render.cpp, while the call to glScissor
always had the right values.

This may be just a janitoral job, but could someone add GL_REPORT_ERROR()
after all OpenGL calls? Without it, I think debugging the OpenGL plugin is
impossible.