[gtk+] (8 commits) Created branch wip/multiple-backgrounds

[Cosimo Cecchi <cosimoc src gnome org>]

The branch 'wip/multiple-backgrounds' was created.

Summary of new commits:

  5cefa5f... styleproperty: make background-clip and background-area arr
  10680a9... styleproperty: make background-repeat an array property
  fb634b7... styleproperty: make background-position an array property
  e144df6... styleproperty: make background-size an array property
  eeef2c3... styleproperty: make background-image an array value
  d268624... colorswatch: don't use the clip box directly
  591e8fe... themingbackgorund: render all background layers
  118423c... reftests: add a reftest for multiple background layers