Restore windows and old-gmm compatibility

Windows compatibility

• The compilation was broken on Windows. There was a problem in the SWIG-generated code from the new ELTYPE and MATTYPE class enums. More precisely, the problem was related to the translation of operator<< (which does not become print or __str__ but __lshift__ in python!). I have prevented SWIG from wrapping this function.
• Compilation of Trilinos is automatically disabled on Windows since Trilinos is not compatible with Windows.

Compilation with old versions of gmm

• It is now possible to compile the code with the (old) version of gmm that is bundled with Ubuntus<18. These old versions define std::operator<<(std::vector<double> const &) although the newest version does not. I previously added our own definition of this missing function in the header gmm_extra.h. Obviously, this definition broke the compatibility with the old version of gmm. Now, the TRY_COMPILE feature of CMake is used to check whether this function is already defined or not. This knowledge is transferred to the compiler using the new GMM_DEFINITIONS variable which is dynamically set in FindGMM.cmake (see this file for more details).

Usage of gmsh v4.x

• By default the new version of gmsh (version 4) writes meshes in a new (incompatible) format. I am currently trying to upgrade MshData so that it can read this new format. In the meantime, I have forced gmsh to write its output in version 2 (see gmsh.py). It temporarily solves the problem. We should, however, be careful to avoid gmsh4 commands in the .geo files!

Future new models for mirrors

• I have added several basic .geofiles in mirrors. I will use them in a near future to make additional basic mechanical tests (to be continued).

CTest

• Successful on gaston
• Successful on Windows (without Trilinos)

mirrors/models/cube_hex.geo

+// a cube meshed with hex
+
+
+DefineConstant[ Lx = {  1, Min 5, Max 20, Step 1, Name "Lengths/Lx" }  ];
+DefineConstant[ Ly = {  1, Min 5, Max 20, Step 1, Name "Lengths/Ly" }  ];
+DefineConstant[ Lz = {  1, Min 1, Max  2, Step 1, Name "Lengths/Lz" }  ];
+
+DefineConstant[ Nx = {   1, Min 1, Max 200, Step 10, Name "Mesh/Nx" }  ];
+DefineConstant[ Ny = {   1, Min 1, Max 200, Step 10, Name "Mesh/Ny" }  ];
+DefineConstant[ Nz = {   1, Min 1, Max 200, Step 10, Name "Mesh/Nz" }  ];
+
+lc = 1; // useless
+Point(1) = { 0,   0, 0, lc};
+Point(2) = { Lx,  0, 0, lc};
+Point(3) = { Lx, Ly, 0, lc};
+Point(4) = { 0,  Ly, 0, lc};
+
+Line(1) = {1, 2};
+Line(2) = {2, 3};
+Line(3) = {3, 4};
+Line(4) = {4, 1};
+
+Line Loop(5) = {1, 2, 3, 4};
+
+Plane Surface(6) = {5};
+
+Transfinite Line {1, 3} = Nx+1 Using Progression 1;
+Transfinite Line {4, 2} = Ny+1 Using Progression 1;
+
+Transfinite Surface {6};
+Recombine Surface {6};
+Extrude {0, 0, Lz} {
+  Surface{6}; Layers{Nz}; Recombine;
+}
+Physical Volume("Volume") = {1};
+
+Physical Surface("FaceZ0") = {6};
+Physical Surface("FaceZ1") = {28};
+Physical Surface("FaceY0") = {15};
+Physical Surface("FaceX1") = {19};
+Physical Surface("FaceY1") = {23};
+Physical Surface("FaceX0") = {27};
+
+Physical Line("Line1") = {13};
+Physical Line("Line2") = {14};
+Physical Line("Line3") = {18};
+Physical Line("Line4") = {22};
+
+
+