localize answer, fix #150677

localize answer to match localized multiple choice option
Added lots of debugging lines. Changed no real code, but seems to work!
Parallel line Q now looks for 1 parallel line with a simultaneous intersection with two compasses
Clean up debug code ready to create pull request
i18n, fix #161076

* don't calculate with localized decimals
* add space after comma in comma separated list
use circle for solution unit
Merge pull request #161334 from pjmattingly/master

Updated moduleDependencies, "interactive" to reflect correct dependencies
Add reminder to rationalise the denominator

Reviewers: eater

Differential Revision: http://phabricator.khanacademy.org/D7851
Add full stops
Create toNumericString function

Summary: If you can make this better, I'd appreciate any feedback (coding style as well as edge cases).

Test Plan:
```
Try out with ( . is undefined, * is all)
- Math.PI           pi / .          # π
- -Math.PI          pi / .          # -π
- Math.PI / 2       pi / .          # π/2
- -Math.PI / 3      pi / .          # -π/3
- -3*Math.PI/2      pi / .          # -3π/2
- .77               percent         # 77%
- -.77              percent         # -77%
- 3/2               mixed           # 1 1/2
- -7/2              mixed           # -3 1/2
- -.001             mixed           # -1/1000
- 1.5               improper / .    # 3/2
- -1.5              improper / .    # -3/2
- -.5               improper / .    # -1/2
- 5                 *               # 5
- 1                 *               # 1
- -1                *               # -1
- .0001             *               # 0.0001
- -.0001            *               # -0.0001
- Math.PI - .01     *               # 3.1315926535897933
```

Reviewers: jack

Reviewed By: jack

Subscribers: alpert

Differential Revision: http://phabricator.khanacademy.org/D7500
substate KAS

Test Plan: none
Fixes the 0pi case for toNumericString

Test Plan:
Shouldn't show up as 0pi anymore (the symbol not the string "pi")

Auditors: jack
Use coefficient answer type in slope_intercept_form

Test Plan: Leave first box blank for http://exercises.ka.local/exercises/slope_intercept_form.html?debug&problem=show-points-and-or-graph&seed=146

Auditors: alpert
Fix broken promise on next problem attempt: Only attempt to show related videos if the Exercises.RelatedVideos module is defined

Summary: ^

Test Plan: Go to a 6th-grade exercise on the iPad, and answer it correctly. Hit 'next problem', and then see the next problem!

Reviewers: mgp, alpert

Reviewed By: alpert

Differential Revision: http://phabricator.khanacademy.org/D7898
Merge remote-tracking branch 'origin/master'
Add build/lxml to .gitignore
More explanation of GCF

Reviewers: eater

Reviewed By: eater

Differential Revision: http://phabricator.khanacademy.org/D7850
Fix focus update text

Reviewers: eater

Reviewed By: eater

Differential Revision: http://phabricator.khanacademy.org/D7803
Make hints more specific

Summary: Move styles to exernal css file

Reviewers: eater

Reviewed By: eater

Differential Revision: http://phabricator.khanacademy.org/D7849
Move css to external file

Summary: Ensure domain and divisor are not the same

Reviewers: eater

Reviewed By: eater

Differential Revision: http://phabricator.khanacademy.org/D7854