Made the bond vector extraction print out from structure.vectors more informative.
This is in response to James Nyirenda's <jamesn7414 att yahoo dott com> post at
https://mail.gna.org/public/relax-users/2012-05/msg00023.html (Message-id:
<1337916876.99384.YahooMailNeo@...>).
The number of vectors extracted is now being printed out.
