Supoport of OpenBSD
Hey,
Here a merge request which contains two commits:
- support OpenBSD and placeholder for non supported OS.
- a way to control how library builds via standard cmake options, which allows to simplify path to used libintofiy to
pkgcfg_lib_INOTIFY_inotifywhich is required on OpenBSD because port's version of libinotify doesn't installlibinotify.so, instead it installs onlylibinotify.so.123.