toolbox: made a --add-include that can be used by doxygen to get proper

toolbox: made a --add-include that can be used by doxygen to get proper
         includes in the .h files, since they are parsed out of context by
	 doxygen
Doxyfile: misc fixes, use ./toolbox --add-include as filter for sources.
include/vlc_common.h: doxygenized VLC_COMMON_MEMBERS

With these changes, and a slightly patched version of doxygen (which you can
get here: http://www.idi.ntnu.no/~sigmunau/doxygen-vlcpatched.tgz ) you should
be able to get some useful documentation out of the vlc sources.