Angle Addition per Trello Card #418
Merge pull request #18481 from imranghory/number_line_clarity

Number Line 3: Replace terms bigger/smaller with greater than/less than for clarity
Move input inside label
counterexample is one word
Don't blow up on missing qtip (for local dev)
Focus radio button on click to allow <enter>
changes in response to comments
minor formatting in code
Update style in khan-exercise.js
Merge pull request #18819 from beneater/lint

Update style in khan-exercise.js
Missing var :(
Wrap radio button lines nicely
minor change so everything stays in red box
minor change so everything stays in red box
Merge pull request #18470 from Christi/interpreting_linear_equations

added labels to fix #18432
7 factoring exercises + small fix to math-model
factoring challenge (won't be used)
fix mathjax config in tests + simplification options
added simplifyOptions parameters to format and parseFormat
We have to get rid of any external scripts in an exercise's html *before* it gets shoved into a jQuery object, otherwise IE8 will attempt to fetch this script. Fix those crazy 404s! #FIXIT