Build procedure for CrystalFp.

The library uses CMAKE as its build system. There is a switch that can be set during configuration to enable OpenMP usage to speedup fingerprint and distances computation. As usual the kind of build (Release or Debug) should be selected on Linux. On Windows the build types are available in the generated Visual C++ project.

CMAKE generates other two targets: "doc" generates the library interface documentation. Instead "devdoc" generates documentation for the developers for all sources.