Draw lines over meshfills when meshfill.mesh is set.

Ref #549.
Merge branch 'master' into 549-meshfill-lines
ok now works properly with right color

now adding a test for this
ok added test
fix #549
Merge pull request #902 from UV-CDAT/549-meshfill-lines

Draw lines over meshfills when meshfill.mesh is set.
Merge branch 'master' into vtk_labeled_contour_for_aashish