Feature: Added a new setting to allow a different custom theme image to be set for child themes (one image applies to all child themes)
Feature: Automatically bypass browser and server-side caching for the theme image on the Appearance > Themes page and on the WordPress Updates page (caching can result in delays in changes to the image)
Feature: Automatically bypass browser and server-side caching for the branding image (caching can result in delays in changes to the image)
Fix: Child themes may not be correctly ghosted after a child theme update is installed
Fix: The custom theme image is cleared in certain circumstances such as when enabling and/or disabling Ultimate Ghoster
Fix: The Custom Theme Image setting may be applied to themes other than the ghosted theme and its child themes
Fix: Clearing the Custom Theme Image setting may fail to save.
Miscellaneous improvements
