mp4: implement dlna profile and mime computation
plugin: implement parser sorting

Sort the parsers based on its defined order field. The smaller "ordered"
plugin will atempt to parse first.
generic: implemente a generic parser plugin

A generic parser plugin based on libavcoded, initially supporting
mpeg1, mpeg2 and mp3.
Merge pull request #3 from dorileo/master

generic parser and dlna stuffs