Blender Git Loki

Allow cache libraries to store both render and realtime (viewport) data.

This is the default now. It should make workflow a lot more foolproof
and convenient, since having only one of these modes active at a time
very easily leads to broken renders and confusing situations.

The problem is mostly due to the complicated way the depsgraph layer
feature is used to handle duplicator visibility. The duplicator is
declared as a child of its group's objects (even though no real
dependency exists!), so that a visible duplicator triggers updates of
invisible group objects, making instances of hidden groups possible.

However, dupli caches have to disable this dependency in order to avoid
unnecessary costly updates in hidden layers which are overridden by
cached data anyway. At the point where these dependencies are created
the evaluation context is unknown though, which means we cannot
distinguish between render and realtime evaluation for the purpose of
cache reading ...