Reworked notification-ui.xml to add state info.

new file:   images/error.png
new file:   images/masks/notification_image_mask.png
new file:   images/no_artwork.png
modified:   notification-ui.xml
Added the new warning and check states to notification-ui.xml.

new file:   images/check.png
new file:   images/check_fullscreen.png
new file:   images/error_fullscreen.png
new file:   images/warning.png
new file:   images/warning_fullscreen.png
modified:   notification-ui.xml
Added new damaged,damaged_fullscreen and no_artwork_fullscreen images.
Modified the no_artwork and warning_fullscreen images.
Modified the image and image state area definitions as recommended by Jean-Yves Avenard.

new file:   images/damaged.png
new file:   images/damaged_fullscreen.png
modified:   images/no_artwork.png
new file:   images/no_artwork_fullscreen.png
modified:   images/warning_fullscreen.png
modified:   notification-ui.xml
Bumped version 4.22.
modified:   themeinfo.xml
Merge branch 'Experimental'

Update branch Master to Experimental.
Added new busy state to notification-ui.xml.

new file:   images/busy.png
new file:   images/busy_fullscreen.png
modified:   notification-ui.xml
Bump version to 4.30.

modified:   themeinfo.xml