When Toaster removes a package from a custom image, it must
also always remove the advised reverse-dependent recipes. 
Similarly, when adding a package it must always add its advised
the packages it depends on.

Toaster normally waited until a new custom image was built before
creating the custom layer and the recipe. However, a different build
can fail because the recipe has already been added to the project, so
the image's default recipe must be created when the image is created.