Switches to soundmanager instead of audio-js.
Ignore mp3s and pdfs in content folder in .gitignore
Only remove final part of extension when building title from filename.
Show "Add coach" button EVEN when there are currently no coaches. :)
Direct students to /learn/, and teachers to coach report, upon login.
Merge branch 'sound_manager' of https://github.com/rtibbles/ka-lite into sound_manager
Merge pull request #2479 from jamalex/updates_for_demo

Updates for demo
Updated soundmanager with user-facing GUI and progress tracking.
Don't show "None" for descriptions (more debugging needed).
Removed unused bar-ui.js file.
Merge pull request #2480 from jamalex/sound_manager

Updated audio player to use SoundManager 2
Have the top left KA Lite icon redirect to the /learn/ tab for now.
Merge pull request #2481 from jamalex/sound_manager

Have the top left KA Lite icon redirect to the /learn/ tab for now.