Change the queue mechanism to make it less confusing (#65)
* Change the queue mechanism to make it less confusing
Fix #2
Now, when you double-click on a song, it is played and other songs of the current list are added to the queue.
Also improved the style of some parts of the code, and changed many Gee.HashMap<int, Media> to ArrayList<int, Media> (they were acting as arrays, I don't know why they were maps).
* Remove `this` when possible
* Use GObject construction as much as possible
* Use Playlist.get, Playlist.set and Playlist.iterator when possible
* Soft-copy lists in ListView.vala
* construct accessor on properties needing it
* Make Noise.Plugins.CDView.dev public to support construct
* Fix many GObject warninsgs and segfaults
* Make it possible to jump to a specific track from the queue