[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.
Add python-dev
[fix bug 966976] Display ng reports on mozillians dashboard.
Merge pull request #628 from akatsoulas/966976

[fix bug 966976] Display ng reports on mozillians dashboard.
[Fix bug 899090] Add extra range/radio polls when no initial available.
Merge pull request #641 from johngian/899090-add-poll-without-existing

[Fix bug 899090] Add extra range/radio polls when no initial available.
[fix bug 972715] Update mozillian username more often.
Merge pull request #643 from akatsoulas/972715

[fix bug 972715] Update mozillian username more often.
[fix bug 967026] Send email notice when a Rep is inactive.
Merge pull request #638 from akatsoulas/967026

[fix bug 967026] Send email notice when a Rep is inactive.
[fix bug 973862] - Make New Voting creation happen in same window
Merge pull request #644 from sayanchowdhury/973862

[fix bug 973862] - Make New Voting creation happen in same window
[fix bug 973011] Make new event creation happen in same window.
Merge pull request #645 from rishabhsixfeet/iss973011

[fix bug 973011] Make new event creation happen in same window.
[fix bug 978294] Allow Council group to edit and delete featured reps.
Merge pull request #650 from glogiotatidis/978294

[fix bug 978294] Allow Council group to edit and delete featured reps.
[Fix bug 979193] Enable markdown in NGReport activity description.
Merge pull request #652 from johngian/fix-markdown-fields

[Fix bug 979193] Enable markdown in NGReport activity description.
[fix bug 979186] Update twitter links