Adding file converter utilities to main CMakeLists.txt.
Small changes for compilation with OGS-6.
Using Polyline::getPoint() for accessing polyline data.
Corrected include path.
Fixed include dependencies.
Fixed linker error linking Utils/FileConverter programs.
Removed unused libraries from library list for the linker.
Small changes to fix compile errors in OGS-6.
Using OGS-6 data structures to read the mesh.
Commented out most of the code.

If we need this tool in OGS-6, we have to reimplement it.
Using logog and TCLAP in ConvertSHPToGLI.cpp
Added simple program to convert OGS meshes into vtk format.