dynamic_background 7.x-2.0-rc3

This release contains may issues found and fixed by Damien McKenna. It also addresses the new image style security fix, which prevented the use of image styles on background images.

* Updated module to match the new Drupal 7.20 image style security fixes
* Fixed issue with JS and CSS files not being loaded
* Issue #1908796 by DamienMcKenna: Fixed dynamic_background_user_upload_form_submit should only process its images, not all of them
* Issue #1908780 by DamienMcKenna: dynamic_background_user_upload_form_validate should be a submission callback
* Issue #1878242 by DamienMcKenna: Fixed if "User supplied images" set to 0, fieldset still shows
* Issue #1878066 by DamienMcKenna: Provide an option to automatically inherit the background of the parent page based on the URL
* Issue #1878056 by DamienMcKenna: Default to enable backgrounds on all content types
* Issue #1888648 by DamienMcKenna: Added drupal_alter() around the image selector
* Issue #1880498 by DamienMcKenna: Fixed DB Node: On content type selection, do not show empty brackets
* Issue #108450 by DamienMcKenna: Improve usability of main "background images" page
* Issue #1878220 by DamienMcKenna: Added thumbnails image styles to image selection forms
* Added support for random images in the extension modules
* Added support for selecting a higher number of images to upload
* Added support for random image selection in the main module
* Issue #1853134 by cableman0408: Undefined index in dynamic_background_set_active_node_image for the node extension module
* Removed test cases from the module as they do not apply to this branch
* Fixed coding style (mostly trailing spaces)
* Issue #1743792 by Andrew_Mallis: Fixed filtering of HTML in node descriptions for dynamic background node