Handle negative and fractional outputs from SMTLIB.

Handle the negative and fractional outputs from SMTLIB.  This required
extending the SMTLIB output grammar to accept negative and division operations.
Currently the support is cheated some, so that only the necessary pieces are
actually parsed.  Further support for more operations will require extending
the support further.

git-svn-id: https://groke.mcmaster.ca/svn/grad/colin/branches/TableTool_javization@10724 57e6efec-57d4-0310-aeb1-a6c144bb1a8b