Fix pvs check to work on numbers always, and work if the string changes.

Instead of assuming the number is always at a certain position, use a regexp
to find it.  It basically looks for "PVS Version 0.0", and only uses the 0.0.


git-svn-id: https://groke.mcmaster.ca/svn/grad/colin/trunk/TableTool@10203 57e6efec-57d4-0310-aeb1-a6c144bb1a8b