Code cleanup: indentation
OSX/python: update to py 3.4
Some style cleanup in sound area.
Fix T39607: Audio not in synch when the blend file loads.

Root of issue is probably in AUDASPACE itself (or even in OpenAL?).
Issue not present with SDL backend, only OpenAL afaik.

For now, workaround in Blender is to call seek twice when starting play
(not needed when resuming from pause).
Fix T39610: Shared mesh used for Mesh Deform causes crash

For now disable using linked edit mesh in the meshdeform modifier.

This is because editbmesh_get_derived_cage_and_final() might easily
conflict with the thread which evaluates object which is in the edit
mode for this mesh.

We'll support this case once granular dependency graph is landed.
Fix T39284: clamp cycles volume density to be >= 0, to avoid accidental strange shading.
Fix cycles standalone not writing images in background mode properly.
Fix T37675: blender internal viewport render wrong for volumes after rotation.

We really should not have Object.imat_ren, that's the wrong place to put render
data. But just update it now on rotation rather than doing a bigger refactor to
remove it.
Fix T39743: Crash when deleting faces in with new autosmooth.

Odd I did not catch this one... :/
Various fixes/improvements regarding BMesh's elem_index_dirty and BM_LOOP handling.

Most notably, BM_LOOP and BM_FACE index recompute should now be fully decoupled.
Math Lib: avoid having to pass a pre-calculated normal tot area_poly_v3

add normal_poly_v3
Structural cleanup and improvements for the compositor.

Many parts of the compositor are unnecessarily complicated. This patch
aims at reducing the complexity of writing nodes and making the code
more transparent.

== Separating Nodes and Operations ==

Currently these are both mixed in the same graph, even though they have
very different purposes and are used at distinct stages in the
compositing process. The patch introduces dedicated graph classes for
nodes and for operations.

This removes the need for a lot of special case checks (isOperation etc.)
and explicit type casts. It simplifies the code since it becomes clear
at every stage what type of node we are dealing with. The compiler can
use static typing to avoid common bugs from mixing up these types and
fewer runtime sanity checks are needed.

== Simplified Node Conversion ==

Converting nodes to operations was previously based on "relinking", i.e.
nodes would start with by mirroring links in the Blender DNA node trees,
then add operations and redirect these links to them. This was very hard
to follow in many cases and required a lot of attention to avoid invalid
states.

Now there is a helper class called the NodeConverter, which is passed to
nodes and implements a much simpler API for this process. Nodes can add
operations and explicit connections as before, but defining "external"
links to the inputs/outputs of the original node now uses mapping
instead of directly modifying link data. Input data (node graph) and
result (operations graph) are cleanly separated.

== Removed Redundant Data Structures ==

A few redundant data structures have been removed, notably the
SocketConnection. These are only needed temporarily during graph
construction. For executing the compositor operations it is perfectly
sufficient to store only the direct input link pointers. A common
pointer indirection is avoided this way (which might also give a little
performance improvement).

== Avoid virtual recursive functions ==

Recursive virtual functions are evil. They are very hard to follow
during debugging. At least in the parts this patch is concerned with
these functions have been replaced by a non-virtual recursive core
function (which might then call virtual non-recursive functions if
needed). See for example NodeOperationBuilder::group_operations.
Fix T39234: popup menus behave poorly when they have not enough width for all their columns.

Issue fixed by:
* Not having constant width for all columns, but adapt each to its content's width;
* Adapting undo's menu height to undo list length (so that we never have more than three columns).

It is still possible to get issues in extreme cases (small screen, high DPI size,
long op names everywhere...), but this should now be rare corner cases.

Also fixes a minor glitch with undo menu (first column had one item less than the others...).
Move binary-search threshold used for FCurves to BKE_fcurve.h header

Since this is now pretty much the de-facto "minimum distance between keyframes",
we might as well expose this in this header so that other places which need similar
thresholds can perform similar checks (needed for my next commit)
Optimisations for building "Long Keyframes"

For a long time, one of the bottlenecks when drawing summary channels in the dopesheet
(especially with many objects) was how the long keyframes feature (i.e showing holds
between keyframes) got built. Specifically, it was the step where we check on the previous
keyframe to see whether there's a hold between those two.

The old code performed some elaborate checks, which made sense back when we used to handle
certain summary channels (e.g. object-action/ipo, and groups IIRC) differently. However,
nowadays, everything just does it by going over the FCurves one by one, so the offending
code wasn't really providing much benefit. Unless I've forgotten some other reason why
that old method is necessary, this commit should provide a decent speedup here, making
things somewhat interactive now (if still a bit jerky).

Other Tweaks:
1) Introduced float-precision threshold when checking to see whether an existing long
   keyframe could be reused. This should hopefully reduce the number of fp-jitter issues
   when creating summaries for many channels, reducing the number of duplicates created.
2) Precompute colours used for shading the long keyframes, instead of recomputing for
   each block.
Use binary search threshold when deciding whether to create ActKeyColumns too...
Fix T39685: triangulation modifier creates zero-area faces
Building with C++ guarded alloc works again
Fix regression, sculpting on mesh with matcaps (without multires/
Fix T39607: Audio not in synch when the blend file loads.

The problem here was that animation buffers got initialized with zeros in the beginning for unknown parts. Now it gets initialized with the first known value.
The bug's result was that the animation of the pitch started with 0 on first playback and thus any seeking while the pitch is zero resulted in seeking to the beginning.