Compile unit_FEM without unit_MATLAB

[jcmadsen]

should it be possible to compile unit_FEM without unit_MATLAB? Currently I need to make some changes to demos/fem/CMakeLists.txt to be able to compile this (in windows, msvc 2010)

[tasora]

Hi Justin,
you're right, previously unit_FEM was 100% independent from unit_MATLAB, but lately I was doing tests where the precision of the MINRES solver of C::E wasn't enough so I plugged in the MATLAB linear solver in those few demos for the FEM unit, and now one get the error that you saw if you compile unit_FEM & its demos without having unit_MATLAB.
Sorry, this was for testing, but in the release version we have two options to fix this:

1. rework the demos so that they use C::E MINRES (hoping that we can plug some good preconditioner for that moment)
2. or I'll modify the CMakeList so that one can compile unit_FEM only conditionally if unit_MATLAB is compiled too.
   Alessandro