Implemented Tet inner product wrt deriv basis.
Tested helmholtz on tet mesh.
Removed generation of boundary conditions in ContField3D (handled by DisCont)
Fixed FldToVtk to use even-spaced points in 3D.
Cleaned up tet orientation in MeshConvert.
Added utility for generating auxiliary fields 
  (currently generates \nabla u X \nabla v)


git-svn-id: https://gforge.sci.utah.edu/svn/nektar/trunk@2259 305cdda6-5ce1-45b3-a98d-dfc68c8b3305