Blender Git Loki

Commit message and the brunt of the code courtesy of intrr, apologies for the
size of this;


Finally, the Sequencer audio support and global audio/animation sync stuff!
(See http://intrr.org/blender/audiosequencer.html)

Stuff that has been done:

./source/blender/blenloader/intern/writefile.c
./source/blender/blenloader/intern/readfile.c

Added code to make it handle sounds used by audio strips, and to convert
Scene data from older (<2.28) versions to init Scene global audio settings
(Scene->audio) to defaults.

./source/blender/include/BSE_seqaudio.h
./source/blender/src/seqaudio.c

The main audio routines that start/stop/scrub the audio stream at
a certain frame position, provide the frame reference for the current
stream position, mix the audio, convert the audio, mixdown the audio
into a file.

./source/blender/makesdna/DNA_sound_types.h

Introduced new variables in the bSound struct to accomodate the sample
data after converted to the scene's global mixing format (stream, streamlen).
Also added a new flag SOUND_FLAGS_SEQUENCE that gets set if the Sound
belongs to a sequence strip.

./source/blender/makesdna/DNA_scene_types.h

Added AudioData struct, which holds scene-global audio settings.

./source/blender/makesdna/DNA_sequence_types.h

Added support for audio strips. Some variables to hold Panning/Attenuation
information, position information, reference to the sample, and some flags.

./source/blender/makesdna/DNA_userdef_types.h
./source/blender/src/usiblender.c

Added a "Mixing buffer size" userpref. Made the versions stuff initialize
it to a default for versions <2.28.

./source/blender/makesdna/DNA_space_types.h
./source/blender/src/filesel.c

Added a Cyan dot to .WAV files. Any other suggestions on a better color? :)

./source/blender/src/editsound.c

Changes (fixes) to the WAV file loader, re-enabled some gameengine code that
is needed for dealing with bSounds and bSamples.

./source/blender/src/editipo.c
./source/blender/src/drawseq.c
./source/blender/src/editnla.c
./source/blender/src/space.c
./source/blender/src/drawview.c
./source/blender/src/renderwin.c
./source/blender/src/headerbuttons.c

- Created two different wrappers for update_for_newframe(), one which scrubs
the audio, one which doesn't.
- Replaced some of the occurences of update_for_newframe() with
update_for_newframe_muted(), which doesn't scrub the audio.
- In drawview.c: Changed the synchronization scheme to get the current audio
position from the audio engine, and use that as a reference for setting
CFRA. Implements a/v sync and framedrop.
- In editipo.c: Changed handling of Fac IPOs to be usable for audio strips as
volume envelopes.
- In space.c: Added the mixing buffer size Userpref, enabled audio scrubbing
(update_for_newframe()) for moving the sequence editor framebar.

./source/blender/src/editseq.c

Added support for audio strips and a default directory for WAV files which
gets saved from the last Shift-A operation.

./source/blender/src/buttons.c

Added Scene-global audio sequencer settings in Sound buttons.

./source/blender/src/sequence.c

Various stuff that deals with handling audio strips differently than
usual strips.