Now able to play a single file, in a format supported by your browser.
* Playlists not yet supported.
* Volume is a simple on/off switch.
* Repeat / Random not yet supported.
Also includes misc fixes
* Use CSS modules for all the CSS.
* Fix a bug in the filterbar which was not filtering anything.
* Fix a l10n issue in songs view.
* Update hook to clean build repo before running, preventing to push
dev built code.
* Update webpack build code.
