tree_editor: Add the query set to the returned result set in the INCLUDE_ANCESTORS case.

Django ORM is intelligent enough to optimise away the superfluous filter clauses in the common unfiltered case.
White space changes.
Finished feature optimise_include_ancestors.
Merge branch 'next' into tabbed_options

* next:
  White space changes.
  tree_editor: Add the query set to the returned result set in the INCLUDE_ANCESTORS case.