Modules.am: link mkv demux with mp4 demux
mp4/*: export some functions needed by mkv demux

nastyness to a central location. Improves the general readability in my
opinion.

when needed. Zlib-compressed vobsubs work for me now.

* added some clarifications on use of bootstrap to HACKING file

* if http:// and mime == asf, and name doesn't contain asx (cause they have mime == asf too) then bail http access and let the mms access try.
  ( VLC now plays http:// urls which are actually mms:// streams and no longer handles asx files when the path doesn't contain "asx" )

* added the aacp (aacPlus) mime type and force the aac demux in that case. aacPlus still doesn't work. (decoder issue?)

* don't PLAYLIST_GO on a redirect. gave weird effects because the current item was still in the 'open' fase. The playlist is already playing, so there is no use in this option.

  API. ByteCount positions are not supported anymore.

* modules/access_output/udp.c: if a packet is bigger than the mtu size, we emit a warning and try to split it.

* modules/mux/mpeg/ps.c: make sure the data blocks containing the pack and system headers are timestamped correctly. Added an --sout-ps-dts-delay option.

* src/playlist/item.c: fixed recent playlist item initialization bug which was screwing up things like doing random autodeletions, etc...

  fen: any suggestions for the other Control() stuff?

   - searching is a mess
   - autodetect not yet activated, force by opening the idx as subfile

* src/video_output/vout_subpictures.c: modify the scaling factor based on the original video size info.