[GMSH2OGS] Using logog.
[GMSH2OGS] Changed the way the GMSH file is read.
Using TCLAP for command line parsing. Implemented opportunities to write old and new OGS mesh file format.
[GMSH2OGS] More specific desc. of gmsh file format.
[GMSH2OGS] Clearer parameter name and better desc.
[GMSH2OGS] If file extension is not msh and not vtu, set it to vtu.
[GMSH2OGS] Added const to some objects.
[GMSH2OGS] Check: Is mesh read correctly?
[FileIO] Check if at least one element is read.
[FileIO] Parsing fmt and ver. in GMSHInterface::readGMSHMesh().
Merge pull request #329 from TomFischer/GMSH2OGS

Bug fix and new features for tool GMSH2OGS