I took this oportunity to rewrite some parts of the application, make some refactoring and some cleanup and also add some new features and improvements (plugins are now written in pure javascript, linux build is cross-desktop, services can be turned into standalone apps,...).

Major changes:

- web streaming services are now written in pure javascript
- QtWebEngine port
- add Spotify service
- build is now cross desktop (no more desktop specific specialised builds)
- add ability to turn a streaming service into a standalone app
- Rdio: remove service
- Mixcloud: improve integration (add abitliy to seek into the cloudcast)
- Deezer: fix art url missing and disable addToFavorites action