Merge pull request #128 from jwj61/develop

OPL-update update
Merge branch 'develop' of https://github.com/openwebwork/webwork2 into develop

Conflicts:
	htdocs/js/apps/LibraryBrowser/LibraryBrowser.js
	htdocs/js/apps/LibraryBrowser/library_browser.js
	htdocs/mathjax
	htdocs/themes/math2/lbtwo.template
	htdocs/themes/math3/ur
	htdocs/themes/math4/lbtwo.template
	lib/WeBWorK/ContentGenerator/Instructor/ProblemSetList3.pm
	lib/WeBWorK/ContentGenerator/Instructor/SetMaker3.pm
French translation 3
Merge remote-tracking branch 'upstream/develop' into develop
Update math4.css

Addressed bug 2647
Fixed broken disabled buttons
Conditional release initial commit. Allows instructor to specify that a set will not become visible until a sufficiently high score is obtained on another set.
Updates to conditional release. Removed relax_restricted_release. Added feature to warn and ignore nonexistent set names in the restricted release list. Now gives message about restricted release instead of toggling visibility.
Cleanup from rebase
Some conditonal release fixes and tweaks.
Merge branch 'develop' of https://github.com/GravelInnovation/webwork2 into devupdates
Merge pull request #129 from GravelInnovation/develop

French translation part 3
Merge branch 'develop' of http://github.com/openwebwork/webwork2 into devupdates
Made the hr black for problems.  This is so that its easier to use with fractions.
Made the navigation bar hidden when viewed in the pgeditor3 modal.
Updated js libraries.
Merge branch 'develop' of https://github.com/openwebwork/webwork2 into develop
Attempt to try to get LibraryBrowser3 working again.
Updated js libraries.
Make minimum changes to get SetMaker3.pm to work again

Remove direct loading of js files in legacy subfolder.  These are now loaded using requirejs.
Define defaultObject correctly as an empty object as opposed to null. Thanks David.