The atom 'skip' should be handled by 'mov_read_leaf()', not by

'mov_read_default()'. This atom has the same behaviour than the atom 'free'.
patch by (Cedric VINCENT <c-vinc02 at bat710 dot univ-lyon1 dot fr>)
the second part of the patch hasnt been applied, but fixed slightly differently

Originally committed as revision 3276 to svn://svn.ffmpeg.org/ffmpeg/trunk