Major code review, cleaning the code and adding a lot of comments. Also
implements a separate store to keep entities with a reference count and
garbage collection. This closes#15.
Known issues at the moment are:
* Webplayer is no longer working, it has to be refactored.
* AlbumPage is to be implemented.
* Build everything in `public/` folder, to serve only this and avoid
issues with `publicPath` in webpack.
* Moved some icons to FontAwesome and use spinning wheels from
FontAwesome to indicate loading.
* (Very) beginning of a webplayer.
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.
When not setting an endpoint protocol scheme at login, "http" was
assumed. Changing this to the same protocol as current one, to avoid
mixed blocked content.
Also prevent multiple submissions of LoginForm.
