refactoring: split common/matroska.h into three separate header files
refactoring: move MPEG4 object type ID definitions to common header file
common: new codec_c class for codec identification
refactoring: remove unused CodecID definitions
QT/MP4 reader: use codec_c for common codec names
AAC & AC3 readers: use codec_c for common codec names
refactoring: remove unneeded include files
AVC/h.263 & AVI readers: use codec_c for common codec names
CoreAudio reader: use codec_c for common codec names
Dirac reader: use codec_c for common codec names
DTS reader: use codec_c for common codec names
IVF reader, common IVF code: use codec_c for common codec names
Matroska reader: use codec_c for common codec names
MP3 reader: use codec_c for common codec names
MPEG ES reader: use codec_c for common codec names
MPEG PS reader: use codec_c for common codec names
MPEG TS reader: use codec_c for common codec names
OGM reader: use codec_c for common codec names
PGS reader: use codec_c for common codec names
RealMedia reader: use codec_c for common codec names