WIP: Add support for configuring GUI type
For the Plasma Mobile image we need to make the GUI configurable. This means a variety of changes centred around a new option to the build-image command, -g, which can take either "gnome" or "plamo".
For the Plasma Mobile image we need to make the GUI configurable. This means a variety of changes centred around a new option to the build-image command, -g, which can take either "gnome" or "plamo".