I also changed the command line arguments a bit, gl_syncmethod and
gl_sycnwait are used now. Furthermore, I added the ew mode AUTO. This is
a conservative mode and the default for now: if GL_ARB_sync is available,
use the FENCE_SLEEP mode, otherwise, disable it completely.
Conflicts:
include/args.h
misc/args.c
similar/arch/ogl/gr.cpp