Blender Git Loki

Render: Add denoising passes to the Render code

These passes will eventually be hidden from the user, but for now they're really
useful for debugging.

Render API: Allow renderers to allocate additional passes

This commit adds the add_pass function to the renderer API, which allows a renderer
to add a pass to a certain or all render layers. Since the RNA only has 32bit integers as
argument types, the position of the passtype bit is passed instead of the actual passtype.
When additional RenderResults are allocated, all additional passes added to the main result
are added to it as well.

Render: Extend the passtype field of RenderPasses to 64 bit

This commit extends the number of possible pass types to 64 bit. However, it only
affects the structures used for storage during and after rendering, not the SceneRenderLayer
that's visible to the user (due to various limitations to 32 bit integers in RNA).
Therefore, their main purpose is to be allocated by the renderer based on some other setting.

Cycles Denoising: Defaults for the RenderLayer options

Cycles Denoising: Add RenderLayer options

This commit adds the necessary parameters to the RenderLayer panel and syncs them to Cycles.
It would be nicer to define the RNA properties from Cycles Python code like most other ones, but
since that's not possible for RenderLayers, it has to be added in the DNA :/

Cycles Denoising: Implement the denoising data render passes in Cycles

The parameters aren't set anywhere yet since that requires them to be added to the RenderLayer first.

Cycles Denoise: Modify TileManager to allow multiple tasks per tile

This commit changes the TileManager and Session so that one tile can be processed
in multiple steps, here rendering and denoising. The reason for that is that a tile
can only be denoised as soon as all its neighbors are rendered (since the filter window
will cross tile borders) and only be freed as soon as all its neighbors are denoised
(otherwise they wouldn't have the out-of-tile data either).
Therefore, Tiles now have a State and are actually stored for the whole render process.
Tile Highlighting also needed a bit of tweaking to un-highlight tiles between rendering
and denoising.

Cycles Denoising: Change PATH_TRACE task to more flexible RENDER task

This commit renames the PATH_TRACE task to RENDER and adds subtypes to the RenderTile, for now
PATH_TRACE and DENOISE. The reason for doing this instead of simply adding a new DENOISE
task is that it 1. allows to reuse the acquire_tile system etc. and 2. allows to denoise tiles
while others are still rendering (if DENOISE was an own task, it would have to wait until PATH_TRACE
was running out of tiles).
The task isn't used yet, that's for the upcoming commits.