Adding high resolution cover art for Spotify

All we need to do is change the original url (http://open.spotify.com/thumb/<hash>) to one the has one of the following sizes: 60, 85, 120, 300, or 640 so it becomes http://open.spotify.com/<size>/<hash>

300 seemed most appropriate for the Sound applet.

As an additional bonus, it also removes the Spotify watermark.
panel: Use symbolic icons for built-in menu items and the panel right-click menu
keybindings: forgot to update enum list from a c-s-d patch
Renamed region module in cinnamon-settings, switched language-selector-gnome to mintlocale
Moved keyboard layouts to the Keyboard module
Made Keyboard applet point to keyboard settings instead of region
Fix the awful fugly tablet icon
Removed cinnamon-fallback-mounter from the list of required components
Merge pull request #2782 from gillesdemey/patch-1

Adding high resolution cover art for Spotify
Merge pull request #2896 from RavetcoFX/a5

Fix the awful fugly tablet icon
Redesigned options in power/screen modules (wording/layout not final yet)
Improved the layout of the screen module
Cinnamon Settings, power module: Don't show battery/lid info on desktops with no battery/lid
Fixed typos in previous commit
Settings: Layout and fixes in power module
More fixes in cs_power.py
Power module: Fixed widgets not showing when leaving/returning to module
User Details module: fixed Gio warning
Fix regression from:

https://github.com/linuxmint/Cinnamon/commit/3515b554d5f9cd410c9bc9f533c75d171af0b57b
Update desktop files for cinnamon-settings