removed unused var
removed unused var
correct color in hint, fix #135751
add tests for kray util
refactoring
refactoring
refactoring
refactoring
subkatex
Initial arrowheads-at-line-and-ray-ends functionality

Summary: Arrows are clipped at the edge at some angles. :(

Test Plan: http://exercises.ka.local/exercises/graphing_linear_equations.html

Reviewers: joel

Reviewed By: joel

CC: alpert

Maniphest Tasks: T1973

Differential Revision: http://phabricator.khanacademy.org/D5637
Arrowheads shouldn't be dashed if the line is dashed

Test Plan: update khan-exercises substate in graphie-to-png, run graphie-to-png locally, load template #13, observe the arrowheads don't look weird on the dashed lines

Auditors: joel
Make $deg0 use \approx for approximate angles

Summary:
 * Adds the same processing logic used by $len[0-9] to $deg[0-9],
   which displays an approximation symbol before the number if the
   number is rounded.
 * Refactors said logic into KhanUtil.toFixedApprox

Test Plan:
 * Make a movableAngle in the transformer widget in perseus
 * Make a movablePolygon in the interactive-graph widget in perseus

Reviewers: eater

Reviewed By: eater

CC: alpert

Differential Revision: http://phabricator.khanacademy.org/D5671
add parentheses to negative base, fix #146562
remove rounding, fix #146509
Revert "Make problem more concise"

This reverts commit 21fafa8b200ab5fb6461415ae33e96b2418cae32.
Merge pull request #135480 from mauk81/cleanup

removed unused vars
Merge pull request #135948 from mauk81/patch-3

correct color in hint, fix #135751
Merge pull request #140160 from mauk81/test

add tests for kray util
Merge pull request #140991 from mauk81/jslint

jslint
Merge pull request #141040 from mauk81/refactoring

refactoring