Merge pull request #123 from adamarla/master

Changes to support mobile app
Merge pull request #124 from adamarla/master

- refactored some code around getting GradedResponse data to smartphone ...
Merge pull request #125 from adamarla/master

Publish related stuff
Assignment Creation
- Emails to students not to be send unless the assignment is a takehome one.
- Previous commit had this check, but it was removed as the check also prevented solution preview jpegs for takehome assignments from being generated.