Code review request

[GoogleCodeExporter]

Branch name: widget-answer-views-rebased3


Link to the relevant commit(s):
https://code.google.com/p/oppia/source/detail?r=bee60ee4e66b9be322f10846204a114c
7a60175b&name=widget-answer-views-rebased3

https://code.google.com/p/oppia/source/detail?r=9585cf04da955691a33cc943d2eff378
4e62be19&name=widget-answer-views-rebased3

https://code.google.com/p/oppia/source/detail?r=d0e93e9fca9a2365e29947b6ae0eb76e
9b3b89c8&name=widget-answer-views-rebased3

Purpose of code changes on this branch:
- Added new calculations
- Merged with latest develop branch

When reviewing my code changes, please focus on:
Do the new calculations do what we want?

After the review, I'll merge this branch into: develop (only after migration 
will be implemented)

Original issue reported on code.google.com by [email protected] on 23 Jul 2015 at 6:01

[GoogleCodeExporter]

Reassigning to Ben.

Original comment by [email protected] on 28 Jul 2015 at 1:49