#2328 Fixed problems caused by 2 PDEs in Paraview

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@17925 b5f69653-2bf5-0310-8201-b0dafb8e1405
#2326 Now can put Neumann Conditions on coarse mesh. This is not that sensible as this only gives a solution upto an additive constant

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@17926 b5f69653-2bf5-0310-8201-b0dafb8e1405