#79 build failure with libavcodec 51.71.0

[Matt Domsch]

This is related to the fix in SVN noted here:
https://sourceforge.net/tracker/?func=detail&aid=2533619&group_id=141999&atid=751213

The test in src/plugins/ffmpeg/ffmpeg.cpp for
#if LIBAVCODEC_VERSION_MINOR >= 11

causes the (incorrect) top hunk to be compiled (and fail) if libavcodec 51.71.0 (thus _MINOR = 71) is in use. Perhaps the test needs to test for both _MAJOR and _MINOR?

This is on Fedora 10 using rpmfusion provided ffmpeg.