Finally Usable On Device

I am still working through a covid fog, so concentration is poor and progress is arriving in short useful bursts instead of clean, sensible sessions. Still, late last night I finally got the PortMaster build to usable speeds on the Anbernic after all the GLES2 and render-queue work, and that changes the mood of the whole thing a bit: it no longer feels like a theoretical handheld port, it feels like something real enough to keep pushing.