Merge branch 'ww2.5.1.3' of https://github.com/mgage/webwork2-dev into ww2.5.1.3
math4 theme

This includes math4 theme, along with a minor bugfixes and tweaks all around.
Added ability for students to use Past Answers while maintaining current functionality for instructors
Made Classlist editor 2 use tabber.
Made math4 play a little nicer with hardcoded text box lengths
Merge branch 'math4'
Merge branch 'student-past-answers'

Conflicts:
	lib/WeBWorK/ContentGenerator/Instructor/ShowAnswers.pm
Added better integration for essay questions
Tweaking the problem grader
Fixed popover issues on grader page
Fixed popover stuff on problem grader
Merge branch 'math4'

Conflicts:
	htdocs/themes/math4/math4.css
Merge branch 'ww2.5.1.3'
Merge branch 'ww2.5.1.3' of https://github.com/mgage/webwork2-dev into ww2.5.1.3
Merge branch 'ww2.5.1.3'
Merge branch 'ww2.5.1.3' into math4
Merge branch 'develop' of https://github.com/openwebwork/webwork2 into math4

Conflicts:
	conf/localOverrides.conf.dist
	htdocs/js/lib/vendor/bootstrap/js/bootstrap.js
	lib/WeBWorK/ContentGenerator.pm
	lib/WeBWorK/ContentGenerator/Instructor/PGProblemEditor3.pm
	lib/WeBWorK/ContentGenerator/Instructor/ProblemGrader.pm
Merge branch 'student-past-answers' into math4 and fixing stuff from previous merge

Conflicts:
	lib/WeBWorK/ContentGenerator/Instructor/ShowAnswers.pm
Merge branch 'classlist-tabber' into math4

Conflicts:
	htdocs/themes/math4/math4.css
	htdocs/themes/math4/math4.js
Finalizing for push to webwork develop