Fixes #7 partially

[arttumiettinen]

A quick and dirty fix for cgalmesh part of issue #7 (missing regions in cgalmesh output). Support for non-uint8 images and >256 regions is also included. This is probably just a starting point for complete fix but maybe it helps anyway.

[fangq]

thanks @lrineau, sorry for taking this long, had been overwhelmed by department services at the beginning of the semester, and finally have time to start working on iso2mesh.

I just tried to compile your updated source codes on my Ubuntu 16.04 machine (with cgal 4.7) , but it failed with the following error message

[ 25%] Building CXX object CMakeFiles/mesh_3D_image.dir/mesh_3D_image.cpp.o
In file included from /home/users/fangq/space/Libraries/iso2mesh/tools/cgalmesh/mesh_3D_image.cpp:15:0:
/home/users/fangq/space/Libraries/iso2mesh/tools/cgalmesh/initialise_triangulation_from_labeled_image.h:14:33: fatal error: CGAL/license/Mesh_3.h: No such file or directory

is this path specific for cgal 5? can the code accommodate other cgal releases by placing #ifdef macros? thanks

[lrineau]

The file <CGAL/license/Mesh_3.h> has been added in CGAL-4.10. Maybe you can try again with that #include line remove. But the file Mesh_3/include/CGAL/Mesh_3/initialize_triangulation_from_labeled_image.h was added in CGAL-4.9. It might not be compatible with CGAL-4.7.