It is now possible to have the default setting to enable background
images (via theme > enable_background_images) but have a domain turn it
off again as they want to use gradients or specific images.
Upgrading any installation that already has any background_image enabled
will cause enable_background_images to turn on to let it continue to
work.
Including support code that the new install system will utilize, should
not affect existing systems.
Matthew Vale
1e37ce5d3a