Add data-fallback option to regex answer type
Remove debugging
Merge pull request #40870 from petercollingridge/rational-expr

Use separate numerator and denominator answer boxes in Simplifying Rational Expressions 1.
Remove unused code for updating 'exercise message's to tell user about their current proficiency situation in an exercise. _If_ this code is restored in the future, it will no longer belong in khan-exercise.js

Reviewers: eater

CC: alpert

Differential Revision: http://phabricator.khanacademy.org/D2048
whitespace

Auditors: chbl
Merge branch 'master' of http://github.com/Khan/khan-exercises
Make the issue closer script do more and suck less

Test Plan: Ran the script; it closed issues; ran it again and noticed that it no longer found more issues to close the second time around

Reviewers: eater, alpert

Reviewed By: alpert

Differential Revision: http://phabricator.khanacademy.org/D2051
r.json(), not r.json

Turns out I had an old version of requests. :)

Auditors: eater
Get rid of duplicate "problem types" in browse mode

Summary:
Be more in line with how debug mode shows debug info, and store
everything extra related to browse mode in a separate div

Test Plan:
Do a couple exercises in browse mode, notice that the "Problem
types" header and buttons aren't duplicated.

Reviewers: eater, stephanie

Reviewed By: stephanie

CC: alpert

Differential Revision: http://phabricator.khanacademy.org/D2049
Bring in latest i18n.js code.
Tweak hints
Move some strings to be evaluated later, to avoid issues on load.
Oops, typo.
Merging in from stable.
Whitespacing
Focus hints around combinatorics.

Hints focus on binomial theorem with combinatorics. Use Pascal's
triangle as a side note. Fix a bug in computations when x coefficient >
1.
Merge pull request #40936 from jeresig/i18n-exercises

i18n exercises
Add simplifying rational expression 2
Oops.. Fix some syntax errors...

Test plan: Load an exercise and note the lack of syntax errors

Auditors: cbhl, emily
Accept answers where numerator and denominator are both multipled by -1