Misc issues in the tree importer

Also uncovered a syntax error in "quicksave", which is apparently never
tested or used outside of the importer?
Merge pull request #72 from ahinz/bug/bad-method

Misc issues in the tree importer
Template tag for pending permissions

Used in Open University implementation.
Merge pull request #73 from ahinz/topic/new-pending-template-tag

Template tag for pending permissions
Expose tree photo url in API
Merge pull request #74 from ahinz/topic/expose-tree-url

Expose tree photo url in API
Expose orig_owner_id
Merge pull request #75 from ahinz/topic/expose-tree-url

Expose orig_owner_id