Added a coefficient for input numbers.
Merge branch 'master' of https://github.com/Khan/perseus
Switching coefficient checkbox to main answer.
Merge branch 'master' of https://github.com/Khan/perseus
Merge branch 'master' of https://github.com/Khan/perseus

Conflicts:
	Makefile
Being awesome, fixing the coefficient checkbox
Merge branch 'master' of https://github.com/Khan/perseus
Merge pull request #10 from LukeMagill/master

Adding coefficient to numeric input.