+ Refresh feature packs automatically when they change on disk.
+ Remove drag and drop and batch install, and replace it with a single button for installing in the details section.
+ Don't allow multiple copies of the dialog to be opened.
+ Fix a missing brush visible when resizing the dialog.
+ Fix an issue where brushes in the dialog could get deleted resulting in white images.
[CL 2385434 by Frank Fella in Main branch]
