Fix for TIM-449. Do not use Peer UUID

Conflicts:
	apps/openassessment/assessment/peer_api.py
Do not use the submission_uuid from a response for peer
The Workflow API was still using the submission_uuid within a peer response.  Removed this, and updated tests accordingly.
Allow the user to confirm/cancel before submitting a response
Merge branch 'release'

Conflicts:
	apps/openassessment/assessment/peer_api.py
	apps/openassessment/assessment/test/test_peer.py
	apps/openassessment/xblock/test/test_peer.py
Due dates do not apply to course staff

Show dates in staff debug
Add a bash script for cutting a release branch
Merge pull request #271 from edx/will/are-you-sure

WIP: Allow the user to confirm/cancel before submitting a response
Reset scores
Merge pull request #274 from edx/will/instructor-due-dates

Due dates do not apply to course staff
Merge pull request #277 from edx/will/release-script

Add a bash script for cutting a release branch
Merge pull request #269 from edx/will/reset-scores-2

Reset scores (null submission approach)
Display warning if user tries to navigate away from the page with unsaved changes in the response.