[Fixes #81041116] Adds a dictionary cache to NamedScope to improve performance of GetNamedChildren().
Removed old (commented out) code.
Minor changes to named child cache code:
- Remove list when empty
- Style improvements (I think)
- Added comments
[Fixes #81135884] Changes AbstractWorkingSet to dispose quickly, instead of waiting for its write-lock.
Merge branch 'master' into release