[PATCH RSB] Fixes for getting sources

[chrisj at rtems.org]

Hi

These patches fix getting sources for all the packages so releases
can be CI tested to catch breakages closer to the time they happen.

The get sources tool now finds the top level buildset files and only
fetches the sources for them. This avoids processing and handling
configurations that are out of date.

The tool also captures the used buildset and config files and if
all top level buildset files are fetched the unused files can be
listed. This can be used to clean up the repo.

I think it is time to remove old configs. There are some using CVS
or depending on host versions of tools no one runs anymore.

Chris