Added spatial extents to CurveMetaData. Added operator names to Plot state
object.  Added two new curve expressions: CurveDomain (modifies the domain
of a curve) and Curve, a macro wrapping curve expressions on y values 
(normal exprssions) and x values (CurveDomain expression).  Updated 
configuration to test for existence of PyParsing, needed for the wrapper.  
Added to the launcher and dist scripts to ensure the wrapper could be 
found and installed correctly.

git-svn-id: http://visit.ilight.com/svn/visit/trunk/src@6979 18c085ea-50e0-402c-830e-de6fd14e8384