By default the Source Builder now directly installs in the prefix and
does not create tar files. You need to supply options to create build
set level tar files and/or package level tar files.
A build set can invoke another build set. This allows an 'all'
type build set that builds all the RTEMS archs.
Change the get config call to return a map of paths and files.
Add per arch build sets as this is really what RTEMS needs. You
can then vary the version based on the architecture.
Add '%include' to the buildset files.