Merge pull request #305 from ryanakca/kfreebsd

Check if -lcrypt is needed on GNU/kFreeBSD and GNU/Hurd
remove spurious log
Merge branch 'master' into portable
Merge branch 'portable' of https://github.com/poolpOrg/OpenSMTPD into portable
Fix FTBFS on GNU/Hurd due to missing sys/mount.h

sys/mount.h does not exist on GNU/Hurd, they use sys/statfs.h instead. Only
include sys/mount.h if it exists.