c9f93c30c1
Sometimes it might be useful to disable a source for an image, e.g. for a plugin that is not used. This may be to reduce image sizes, or restrict the dependencies necessary to build images. This change adds a new 'enabled' option to each source definition. This allows sources, plugins or additions for each source image to be disabled individually. Change-Id: I31ee0744574fb3db96bee2e9f545600de53d9ee4