OSX: Added new toolbar icons for shuffle/repeat types.

- Properly implemented shuffle and repeat in PlayerPresenter, but the
player shuffling doesn't work yet.
WPF: Several bug fixes, added images for toolbar shuffle/repeat states, added tray icon.

- The tray icon hides/shows the app but there is no contextual menu for
now.
- Several visual and functional bug fixes in PreferencesWindow
(checkboxes did not use the Unchecked event, layout bug fixes, color bug
fixes, peak folder size was not displayed, etc.)
- Revised main menu in MainWindow
- Changed fonts in SyncWebBrowserWindow.
- Fixed build on Android.
Fixed Linux and iOS builds, fixed selected color bug in SongGridViewControl.