Added scrollbar to wallpaper container https://github.com/KanoComputing/kano-settings/issues/128
Added functionality to distinguish between locked and unlocked wallpapers https://github.com/KanoComputing/kano-settings/issues/128
Wallpapers are not displayed in order: default, unlocked, locked https://github.com/KanoComputing/kano-settings/issues/128
Apply button disables and locked wallpapers now use overlay https://github.com/KanoComputing/kano-settings/issues/128
Merge pull request #135 from KanoComputing/unlockable-wallpapers

Unlockable wallpapers