Start of meta engine stuff. src/input/input.c needs to be fixed a bit. I'll finish it today. @zorglub: now you have to use the psz_arturl meta to display stuff in the interface.

Fix compilation for libvlc users

Also, make it clearer what is shared and instance-specific

So,
libvlc_t ==> libvlc_global_t
vlc_t ==> libvlc_int_t (internal instance)

p_object->p_libvlc ==> p_object->p_libvlc_globale
p_object->p_vlc ==> p_object->p_libvlc

VLC_OBJECT_VLC ==> VLC_OBJECT_LIBVLC

And by the way, there is some cleanup required :) (ie, some things are created in the global object instead of the instance-specific one)

* src/misc/messages.c, src/input/input.c: revert 16279 and use OBJECT_FLAGS_QUIET instead when preparsing.

* src/misc/messages.c: if OBJECT_FLAGS_NODBG is specified, don't output any messages at all. That avoids flooding the console with useless messages when preparsing.

    __ppc64__ (meaning PowerPC).

This one happened each time the message queue was overflowed.
Also (hopefully) fixed a leak that would happen each time no message 
queue were found. I don't know if this condition can ever appear though

vlc_input.h: Fixed a not so nasty memleak recently introduced

Thank you very much zorglub

To use it, put a string in p_object->psz_header, all messages from this object and its parent will have the header prepended

Initial support for registering and handling some shared stats 

(da big courmischage)

 * doxygenated parts of the messages system

* include/vlc_codec.h: defines decoders/encoders related structures here.
* include/vlc_video.h: new video_frame_format_t structure which defines the properties of a video frame.
* include/vlc/decoder.h: include vlc_codec.h
* src/misc/objects.c: added VLC_OBJECT_PACKETIZER and VLC_OBJECT_ENCODER object types.
* modules/stream_out/transcode.c, modules/codec/theora.c: experimental theora video encoder.
* src/input/*: some cleanup.

    collisions with a couple of plugins.

    using our va_list twice, which caused crashes on architectures where
    va_list is a pointer; we now use va_copy whenever possible.