Move the video size and rate abbreviations system from libavformat to libavcodec

patch by Stefano Sabatini: [stefano dot sabatini minus lala poste dot it]
original thread:
[FFmpeg-devel] [PATCH] Redesign the video size and rateabbreviations system
date: 06/02/2007 05:30 PM

Originally committed as revision 9288 to svn://svn.ffmpeg.org/ffmpeg/trunk