Wmain

Closes #979

See merge request !370

of command line arguments on Windows using the Windows function
GetCommandLineW() to try to solve #979

warning->error if file to merge does not exist + error when opening non-existant file in batch mode (not an error in interactive mode, as the file can be a new project)

only pass size on node for embedded points in volumes and let HXT compute the boundary size from the boundary edge lengths (instead of calling BGM_MeshSize), as this is what the old Delaunay also does.

Hxt major update with colors to 32 bits

See merge request !369

use "M3D9" type for 9-node quad in INP export (better than falling back to the base class, which is clearly wrong)