Original commit message from CVS:
this adds video4linux2 source and element plugins. The division in v4l2* plugins is the same as for v4l1 - i.e. an element, a src and a sink, but there won't be separate encoding plugins (like v4lmjpegsrc) - all functionality is (thanks to video4linux2) integrated in one plugin: v4l2src. v4l2sink is still to be done, that'll come later.
