Merge pull request #1 from gynsolomon/master

update code
Adjust the show of wrong rate
Merge branch 'master' of https://github.com/liguangsong/mothership
[liguangsong]for Rounding of wrong rate
[liguangsong] for sort problem by wrong rate
[liguangsong] for sort problem by wrong rate
[liguangsong]for adjust the show of problem
[liguangsong]for the show of choices
[yanan] some minor changes about UI and data
[yanan] for dashboard v2 release build
Merge remote-tracking branch 'upstream/master' into course-builder
[yanan] change viewLessonDetails page's title
Merge branch 'master' into course-builder