[mythtv] LastFM support in MythMusic

[Anduin Withers]

> _ZN3MD5C1Ev

Among many other quirks, headers you find that are part of ffmpeg will tend
to lack simple things like conditional extern "C" blocks. Your unresolved
symbol, as Nigel Pearson pointed out, is the C++ version of the symbol for
that function. This isn't what you want, you need something like:

extern "C" {
#include "blah/md5.h"
}

--
Anduin Withers