Alsa + OSS can be included/build at the same time.
Alsa or OSS can be runtime selected with -a.
Add audio thread support to OSS module.
Add polled audio support to alsa module.
Removed some debug source code.
Move objects before $LIBS to avoid link failures with --as-needed.
Do not override CFLAGS for video test.
Rearrange *FLAGS incl. some minor fixes.
Don't override VDRDIR, LIBDIR and TMPDIR in makefile.
Don't abuse LDFLAGS in makefile.
Define CC in makefile.
Include GL/gl.h for the GL_COLOR_BUFFER_BIT definition.
VideoInit() needs an argument.