[Fix bug 966740] Upgrade tastypie to v0.9.16

* Remove hardcoded tastypie directory under vendor-local/lib/python.
* Add tastypie as a submodule.
* Upgrade tastypie to latest release v0.9.16.
* Security fixes in tastypie prevent XSS under /api.
* Remove restricted field from RepResource. Enable upstream caching.
Merge pull request #611 from johngian/tastypie-upgrade

Upgrade tastypie.