On 64bit system KERN_CPTIME systctl gets returned as 64bit uint.
On 32bit system it's returned as 32bit uint. This is not documented anywhere
(or maybe I've missed it). I've added preprocessor test for 64bit system.
- 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