Update year in README
Add (c)
Add matrix transpose test and update other tests to use 'equal' instead of 'equals' to work with qunit 2009+

Summary: Our qunit tests are um, out of date.

Test Plan: Tested locally

Reviewers: eater, alpert

Reviewed By: alpert

Differential Revision: http://phabricator.khanacademy.org/D895
growth mindset A/B test
Fix summatives better

Test Plan:
Did parallel_lines_1 in App Engine land on Chome dev and IE8.
Fix typo in similar triangles 1 hint

Closes #38809.

Auditors: eater
Fix local mode

Didn't see a review for this when it went in -- would appreciate code
reviews for all changes even if they're small.

Auditors: jascha
Fix scientific notation input box size on one type

Closes #38824.

Auditors: michaelchang, eater
Merge branch 'master' of git://github.com/Khan/khan-exercises