Feature/victor/instructor grading

Feature/cale/github status api

Move to a single test.sh file that only runs the relevant tests for a particular branch in the repo. In particular, don't run cms tests on branches derived from master

- has matching changes in controller staff_grading view.

- comments
- more info in log msg
- better error

Fix/brian/nonascii html xmodule

- factor out some common code
- improve variable names

Merge branch 'feature/victor/instructor-grading' of github.com:MITx/mitx into feature/victor/instructor-grading

Diana/instructor grading styling

- no polling, since instructors may take a long time to grade

Don't cap points coming back from CodeResponses

Don't cap points coming back from CodeResponses -- let them be more than max_points if they want to award extra credit.