First Run Experience

This blueprint is about defining BeatBox's first run experience and how to make it nice.

* BeatBox's music library should be located at the XDG music location by default.
    * This may call for a string change on the welcome screen. This would make the locate entry read "Change Music Folder" because by default the music folder is already where your music should be.

* Whenever BeatBox's library is empty:
    * the welcome screen should be shown.
    * The welcome screen should accept file drops in the form of playable audio files.
    * The "Playlists" source should either become insensitive or not be shown. (my first instinct would be to just not show it --DanRabbit)
    * Devices, Stores, and other external music sources should remain sensitive/visible and the welcome screen should not obstruct them.
    * The search bar, play controls, and view switcher should remain insensitive since interacting with them does nothing.

* If an external device containing music is mounted, BeatBox should show an item in the welcome screen explaining that music can be imported from this device and take the user to where he can view the device in BeatBox.