Code review request - Githubissues

Branch name:
for-2.0.0-cardify-pages

Link to the relevant commit(s):
https://code.google.com/p/oppia/source/detail?r=bc45c8641330f24a74abeb445346ccf6
560c8cf2&name=for-2.0.0-cardify-pages

Purpose of code changes on this branch:
To turn certain pages into cards, as well as other small fixes.

When reviewing my code changes, please focus on:
Code Health, NOTE: I changed some wording on the warning text on the signup 
page, which also required changing a test. It's worth checking this to make 
sure I didn't break anything.

After the review, I'll merge this branch into: develop

Original issue reported on code.google.com by amitdeut...@google.com on 3 Mar 2015 at 4:02

oulan / oppia

Code review request #643