HTML5 videojs.com video player implemented as suggested in issue #8
Revert exponents-radicals to non-empty file.

Got deleted due to no longer existing on KA site.

Need their API to match to their live data.
Tweak to wording on facility edit page (thanks Rui!).
Video thumbnails now display for related videos on exercises.
Update to .gitignore and instruction to put independently downloaded
content in content folder.
Add Mac OS X installation instructions.
Merge upstream
Merge pull request #17 from juliaogris/develop

OSX installation instructions
Fixed universal subtitle API download URL.
Added helper function for listing downloaded video youtube ids.
Updated the topic tree. Now in line with the first torrent file's videos.
Merge branch 'develop' of github.com:jamalex/ka-lite into develop
Use .png image for all thumbnail contexts; don't need the .jpg anymore.
Merge branch 'develop' of github.com:jamalex/ka-lite into develop
added /bin/bash to .sh files; should fix #15
other bash fixes
added whitespace to increase readability
Merge pull request #19 from mrshu/bash_everywhere

Fixing running shell scripts always in bash
Initial Implementation of Django Translation
-Check if database exists.
-Check if the user is installing as root.
-Check write permissions.