Openmesh interface

[aschier]

I added a simple OpenMesh interface to integrate BFF with other programs.

It currently generates face-vertex UVs stored at the halfedge of a triangle incident to the vertex and does not try to preserve UV shells, but it is planned to do so.

Support for polygons would be possible, but is currently out of scope in our projects. Currently it can possibly be added rather easy as a wedge corresponds to a halfedge of the polygon and maybe we will include it later.

As triangle structure it depends on https://github.com/aschier/openmesh_structures for mesh traits with double precision, so we avoid using templates and BFF can be installed as a library.

[aschier]

The other commits:

• Fix for the invalid end vector iterator (fixes #29).
• Fix for missing algorithm include (needed at least for MSVC).
• Improved CMake files:
  • Create a library.
  • Provide exported targets.
  • Install targets.
  • Add headers to the targets, so they get listed in cmake output formats which list project files, e.g., Visual Studio projects.
• Added another FindSuiteSparse.cmake file, which works (better) for me. You may need to test if it works for you as well.

[aschier]

I added another commit, that removes the dependency on an external common Traits class by using templates. I currently added a template for the traits and not the mesh, as the interface is only tested for triangle meshes anyway.