Updated graphie-3d to use the painters algorithm.  Added a few more problem types to volume 1.
added some more options to graphie-3d, weird shape now looks snazzier.
Merge pull request #59043 from petercollingridge/multi-rat-exp-4

Fix bug caused by treating term as an expression
Merge pull request #59065 from petercollingridge/sim-rat-exp-4

Fix issue with negative signs and avoid additional cancelling
Merge pull request #58408 from petercollingridge/comp-dec

Add more easily confused questions to comparing decimals
Broke volume_1 into 3 more reasonable exercises.  Volume_with_unit_cubes is just basic understanding of volume by counting cubes.  Volume_1 builds an understanding of the formula for the volume of right rectangular prisms.  Volume_2 uses the knowledge built in Volume_1 for more advanced or creative problems.  Everything is still at the 5th grade level.
Put correct decimal place separators in exercises

Summary:
Use the correct localized decimal place separator in the basic
addition, subtraction, multiplication, and division exercises. Also, allow
changing the icu language at runtime using a lang=LANG parameter.
Fixes T1141

Test Plan:
Visit all the _decimals exercises, make sure they still work. Visit
the exercises with lang=fr, make sure that the decimals are separated using a
comma instead of a period.

Reviewers: eater, alpert

Reviewed By: alpert

CC: james, alpert

Maniphest Tasks: T1141

Differential Revision: http://phabricator.khanacademy.org/D3386
avoid two digits repeating decimal with same number

like *1.**22***
example: [adding_and_subtracting_rational_numbers.html?seed=69&problem=repeating-decimals](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/adding_and_subtracting_rational_numbers.html?seed=69&problem=repeating-decimals&debug)
suggestion from spicyj
ensure that EXPR1 is not divisible by EXPR2, fix #58979
show correct solution hint, fix #59324
Merge pull request #60060 from mauk81/patch-5

show correct solution hint, fix #59324
Calculator improvements

Summary: Add e^x, ln(x), and pi. Default to radians

Test Plan: open law_of_cosines.html in local mode and poke around.

Reviewers: alpert

Reviewed By: alpert

Differential Revision: http://phabricator.khanacademy.org/D3515
Merge pull request #59452 from mauk81/patch-1

avoid two digits repeating decimal with same number
Fixed style issues.
Replace all instances of pi with π

Test plan: Type pi+pi and see π+π

Auditors: alpert
show correct solution hint, fix #60485
Merge pull request #60576 from mauk81/patch-5

show correct solution hint, fix #60485
Merge pull request #58401 from StevenGubkin/master

Volume exercises
Fix "1 more cars parks" bug

Auditors: alpert