Fix #44284

Test plan:
http://localhost:8000/exercises/constructions_1.html?debug&problem=bisector&seed=130&activity=%5B%5B%22incorrect-activity%22%2C%22%5B%7B%5C%22center%5C%22%3A%7B%5C%22coord%5C%22%3A%5B1.3821044240733358%2C-0.6756954962136307%5D%7D%2C%5C%22radius%5C%22%3A3.054911223374956%7D%2C%7B%5C%22center%5C%22%3A%7B%5C%22coord%5C%22%3A%5B-1.3501793543244318%2C0.6600876843363889%5D%7D%2C%5C%22radius%5C%22%3A3.0028746954922076%7D%2C%7B%5C%22first%5C%22%3A%7B%5C%22coord%5C%22%3A%5B1.1203765504343803%2C2.3670176648243846%5D%7D%2C%5C%22second%5C%22%3A%7B%5C%22coord%5C%22%3A%5B-1.178506688074016%2C-2.3378757798322276%5D%7D%7D%5D%22%2C23%5D%2C%5B%22correct-activity%22%2C%22%5B%7B%5C%22center%5C%22%3A%7B%5C%22coord%5C%22%3A%5B1.3821044240733358%2C-0.6756954962136307%5D%7D%2C%5C%22radius%5C%22%3A3.054911223374956%7D%2C%7B%5C%22center%5C%22%3A%7B%5C%22coord%5C%22%3A%5B-1.3501793543244318%2C0.6600876843363889%5D%7D%2C%5C%22radius%5C%22%3A3.0028746954922076%7D%2C%7B%5C%22first%5C%22%3A%7B%5C%22coord%5C%22%3A%5B-1.1798492899935782%2C-2.3396894113710793%5D%7D%2C%5C%22second%5C%22%3A%7B%5C%22coord%5C%22%3A%5B1.1037872368516064%2C2.3665112893286073%5D%7D%7D%5D%22%2C11%5D%5D

Auditors: cbhl
newProblem gets fired on Exercises, not Khan.

Fixes debug mode.

Test plan:
locally, Chrome/OS X
- Visited http://localhost:8000/exercises/addition_1.html?debug and
  http://localhost:8000/exercises/angles_of_a_polygon.html?debug and clicked on
  problem history, random problem, and different problem types.

Auditors: eater, alpert
Run a Reprocess on #solutionarea to fix fonts

Closes #44265.

Test Plan:
Loaded /exercises/square_roots_2.html a bunch of times and it looked nice.

Auditors: eater, cbhl
Don't accept unanswered questions for basic_set_notation

Test plan:
In local mode,
- Leave the answer area blank and submit. Answer shouldn't be accepted.
- Enter something in the text box and submit. Answer should be marked wrong.
- Check the checkbox and leave the text box blank. Answer should be marked wrong.
- Enter something in the text box AND check the checkbox. Answer shouldn't be accepted.
- Enter the correct answer. Answer should be marked correct.

Auditors: cbhl
(Hackily) fix issue with resizing circles in IE8

fix #43634; fix #43405; fix #43922

Test plan: Try adjusting the radius of the circle in graphing_circles_2 exercise locally in Chrome and IE8

Auditors: alpert
Remove newlines before comparing multiple choice answers

fix #44356

Test plan: Resist suicidal urges while testing divisibility exercise in IE8

Auditors: alpert, cbhl
Add simple answer types unit test

Test Plan:
Ran the test in Chrome and IE8. In IE8, it passes now but fails when
aac2fa7 is reverted, as it should.

Auditors: eater, cbhl
Moar unit tests!

Test plan: Hit http://localhost:8000/utils/test/answer-types.html in Chrome and IE8

Auditors: alpert
Nix console.log()s

Test plan: run unit tests and note the absence of logging

Auditors: alpert
Moar unit tests and stuff

Test Plan:
Hit /utils/tests/answer-types.html in Chrome.

Auditors: eater
Add a predicate answer type

Summary: I really hope this doesn't break _All The Things_

Test Plan:
Create a test exercise with a solution like this:

    <div class="solution" data-type="predicate" data-forms="integer">function(n) { return n === 5; }</div>

Test locally, verifying the correct answer is accepted and incorrect answers aren't. Verify the timeline works correctly.

Also check an existing exercise, degrees_to_radians, to verify number answers still work and work if they're part of multiples. Also verify the check answer message appears for pi approximations and verify that the timeline works.

Reviewers: alpert, cbhl

Reviewed By: alpert

CC: Dave

Differential Revision: http://phabricator.khanacademy.org/D2129
Remove unused (global :() variable

Test Plan:
ack correctIndex and run answer-types unit tests.

Auditors: eater
Fix lots of nits; whitespace, global vars, formatting

Test plan: do a few problems of each type locally

Auditors: alpert
Correctly color history nodes for custom answer

Test plan: Answer incorrectly then correctly in an exercise with a custom answer and view the history. Looks ok. Change the exercise such that the last answer in the history is now wrong. View the same history link and see that the last answer is now red, not green.

Auditors: alpert
Get rid of 'literal' form of 'number' answer type

It was introduced in my original refactor in 1c494b28, but that commit
doesn't provide any insight into its original purpose and I can't
remember anything. At any rate, the tests all pass. We'll see what
happens.

Test Plan:
/utils/test/answer-types.html

Auditors: eater
Add calculator to units english

Fix #44560.

Auditors: eater
Update the title tags to match real display names

Auditors: eater
Interpret blank coeficient as 1

Test plan: Answer ["", "3"] to http://localhost:8000/exercises/converting_between_point_slope_and_slope_intercept.html?seed=176&problem=point-to-intercept&debug

Fix #44139

Auditors: dave
I <3 nested tables

Closes #44585.

Auditors: peter
expr() simplifies x^0 and x^1 too much

Fix #44482

Auditors: alpert