Fixes for the tool shed's install and test framework.
Merge with stable.
Fixes for repositories in the tool shed whose repository tip changeset has no files (because they were all deleted) but have valid tools and other utilities in previous changeset revisions.
Fixes for repositories in the tool shed whose repository tip changeset has no files (because they were all deleted) but have valid tools and other utilities in previous changeset revisions.
Merge stable.