Added user variable checking to the full_analysis.py script.
This is in response to Tiago Pais's <tpais att itqb dot unl dot pt> post at
https://mail.gna.org/public/relax-users/2009-10/msg00009.html (Message-id:
<E45CDDF4A4E54B34A36BFBA62E6BFF20@...>).
