This is in preparation for the (L)GPL license upgrade code that will add
version 3 of these licenses.

Originally committed as revision 19114 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 9610 to svn://svn.ffmpeg.org/ffmpeg/trunk

Plus replace one occurrence of "version 2 of the license" with "version 2.1
of the license", same as in the FSF version. This has always been LGPL 2.1.

Originally committed as revision 9609 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 9608 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 4842 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 4749 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 601 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 4 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 2 to svn://svn.ffmpeg.org/ffmpeg/trunk