removed some unused code
add space between equal sign and question mark
update utils
straighten constructions util

* adjust variable name
* remove unused variable
jslint
add calculator

exercise requires dividing by pi
rename angle, fix #119287
Fix for "not showing" bug

I believe it's a pernicious scoping problem because:
- it occurs rarely
- when it does occur, the competing exercise never reaches
`debugLog("loading and rendering " + exid)` on line 1113
- despite not reaching the above, it manages to set `typeOverride` on
line 1077

That is, there are two, almost simultaneous renders (say A and B). A
sets its local `typeOverride` then A sets the global `exerciseId`, then
B sets its local `typeOverride`, then B sets the global `exerciseId`,
then A calls `startLoadingExercise(exerciseId,...)` with the global
`exerciseId`, which was the one set by B.

The only time the global `exerciseId` should be set is in
`setUserExercise`.

The real solution is to change the variable names so that global and
local variables are confused with each other.
Merge remote-tracking branch 'upstream/master' into cleanup
Merge remote-tracking branch 'upstream/master' into cleanup
removed some unused code
removed replaced util from lint_blacklist
removed some unused code
Merge pull request #103000 from petercollingridge/sector

Add radians to exercise type 1
Fix hints
Make fractions a bit simpler
Add radians to circles and arc exercise
Reword hints to be consistent

Auditors: eater
Merge pull request #106664 from petercollingridge/funcinv

Add exercise that require use of expression editor

Auditors: eater
Merge pull request #106715 from petercollingridge/shift_reflect

Make one function dotted so we don't rely just on colour
Improve hints

Auditors: eater
Merge pull request #107979 from petercollingridge/eqifrac

Rewrite hints

Auditors: eater
Merge pull request #108081 from petercollingridge/multimixed

Simplify hints

Auditors: eater
Merge pull request #110216 from petercollingridge/constructions3

Fix inCenter equation
Function to find inradius
Start incircle exercise
update validator
Improve findInscribedPolygon function tests
Put constructions utils back
Finish inscribed circle exericse
Revert to updated constructions util
Circumscribing circle exercise
Function to find inradius and circumradius
Check tool properties properly

Auditors: eater
Merge pull request #113389 from petercollingridge/impfrac

Rewrite hints
Improve hints
Remove unnecessary style

Auditors: eater