added work around for limits 2 error
Fixed again
Fix issue #33473, allow white space in expressions involving subtraction

13-2v or 13 -2v was being accepted, but 13 - 2v was not.
https://github.com/Khan/khan-exercises/issues/33473
Allow whitespace after negation and subtraction.

Add \\s* after all instances of [-\\u2212] in exercises and tested.
There is no reason for counting students wrong for variance in formatting
of this type, and it is not infrequent to see expressions as 5 - x in text.
var tag incorrectly terminated with a /span ending tag

This was causing errors on our local school server by
students with Macs using Safari.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	exercises/limits_2.html
Merge branch 'master' of git://github.com/Khan/khan-exercises
Merge remote-tracking branch 'upstream/master'

Conflicts:
	exercises/limits_2.html
Update limits_2.html
Caesar Cipher Exercises 1-4
Cipher Exercises 1-4: Updated text
Trying to get rid of old commit difference
revert old commit of limits_2 to current upstream version
Tweaks based on user feedback
Added IE10 CSS hack to properly format interactive slider
Cleaned up some tags, fixed Barchart display
Function to extract coeffcient for a given term
Basic solving rational expression exercise
Add answer and fraction simplification
Ensure variables don't cancel