* src/input/demux.c: skip header id3tag in the core before loading the demux (id3tags have a tendency to mess probing).
* modules/demux/flac.c, modules/demux/mpeg/m4a.c,mpga.c: update id3tag parsing.
* modules/demux/util/id3tag.c: id3tag parsing doesn't need to skip the id3tag header anymore.
* modules/demux/util/id3.c: module removed because id3tag header skipping isn't needed anymore.

* modules/demux/aac.c: removed deprecated aac demux (replaced by the m4a demux which uses the m4a packetizer).

- use execlp instead of execl
- perform process replacement in the child process, not the parent
- wait for process termination (to avoid zombies)
- do not return value from void function
- more verbose

- struct addrinfo check

- Added check for getaddrinfo

   arrives too late to the mux.

   VBI teletext descriptor should not set the codec because they only
   add information on a teletext stream.

   facilities. Fixed a few incoherences with
   i_original_channels/i_physical_channels.

   when there is no packet coming (fixes a "packet sent too late" issue
   with the ts muxer).

   downmixing ; completed downmixing options.

   mpga streams.

thing to do.

-- xtophe