On OpenBSD 5.6 sys/ucred.h uses NGROUP define, but misses include to
sys/param.h in which NGROUP is defined. sys/ucred.h is included in
sys/mount.h which we need to get the cached ram. Because of this include
chain our compilation will fail with missing NGROUP define. This can be
resolved by including in our code (and in correct order) system headers.
- Removed OpenBSD stuff from freebsd port
- Renamed bsd folder to freebsd since now it contains only
freebsd-relevant files.
- Changed CMake instructions to account for bsd port changes
- modified main source file to account for openbsd port