FieldConvert not working on Nodal Tris
When trying to postprocess a nodal triangle (for example the Helmholtz2D_CG_P2_Nodes.xml file in library/Demos/MultiRegoins) the method fails. An initial inspection shows that it defaults to TriExp::v_extractDataToCoeffs which is currently only set up to read the Modified Basis (rather than the Ortho baiss that the NOdalTris are based on). However even fixing this we get rubbish solution values despite the error being small in the test.