added htdocs/applets/*.swf to .gitignore these are symlinks added by OPL-update to swf files found in the problem library"
Merge remote-tracking branch 'openwebwork-dev/master'
Updated MathJax submodule to point to a v2.1 revision
Merge pull request #83 from aubreyja/master

Updated mathjax submodule to point to v2.1 and updated .gitignore to ignore new htdocs/applets/*.swf symlinks intoduced by recent update to OPL-update