Update to 3a1. Note that this PR does not supersede ports/56393. The
issues pointed out by ports/56393 are still open. The following is
just an update for the new release and does not include other goodies.
If the repo-copy from lang/slib to devel/slib is not acceptable or
takes much time, just update to 3a1 with retaining the categories
Fix: cvs diff: Diffing .