Scale images in mediabrowser and mediapicker

[burningice2866]

While the CMS tries to do serverside scaling of images when showing them in the mediabrowser and mediapicker to make them fit, this fails for images with a format not supported for serverside resizing.

This can be fixed by adding the following css to the ui-box that contains the image - i believe something like the class .genericview ui|labelbox[image^="/"] ui|labelbody would do

background-size: contain;