Merge branch 'master' into depsgraph_cleanup

Merge master to prepare landing all the work to master.

Depsgraph: Fallback to plain array for operations once depsgraph was fully built

Storing dozen operations in a map is not really efficient for traversal and
looping (which happens A LOT) during graph evaluation. So let's sue map during
building process to speed up some lookups but once graph was finalized we are
now switching to an array for operations.

This solves the speed regression caused by switch to a native BLI utilities
and also gives few percent extra speedup comparing to master. So it's a win.

Depsgraph: Some more simplification of object destruction

Depsgraph: Make sure memory reports stays all grouped

Depsgraph: Simplify some destructors

Depsgraph: Add some utility macro to avoid long typecasts

Depsgraph: Remove unordered set header

Once again it became unused and obsolete.

Depsgraph: Use gset instead of unordreed_unordered_set

Depsgraph: Remove unordered map utility

Is not in use anymore.

Hopefully speed still stays at the same level.

Depsgraph: Use GHash for components in ID node

Depsgraph: Use GHash for operation nodes stored in component

Depsgraph: Use GHash for the id map

Depsgraph: Remove use of std::hash, we have our own functions for that

Depsgraph: Cleanup of util headers

Depsgraph: Use shorter prefix for util headers

Depsgraph: Move PChan map to a builder folder as well

Depsgraph: Cleanup of header files, amke them easier to read

Depsgraph: Use more explicit path to include headers

Makes it easier to see where exactly file is coming from, additionally
should help compiler to find headers quicker.

Depsgraph: Move transitive reduction and cycles solver to builder folder

This algorithms are only used for graph building and having them in util
was causing some bad level includes from util/ to intern/.

Depsgraph: Remove file with just a single debug define

Granularity is good, but it's a bit too extreme :)