added the ability to generate path lines using a period time basis
git-svn-id: http://visit.ilight.com/svn/visit/trunk/src@23206 18c085ea-50e0-402c-830e-de6fd14e8384
git-svn-id: http://visit.ilight.com/svn/visit/trunk/src@23206 18c085ea-50e0-402c-830e-de6fd14e8384