MFC r261892: zpool.8: fix typo in option description of labelclear command
MFC r261893: zfs.8: fix garbled options in a sample zfs send -R command line
MFC r261894: move devd rules for zfs events into a separate file

... and fix stale event types
MFC r271609: add gptzfsboot.8, zfsboot.8 and zfsloader.8 manual pages
Merge remote-tracking branch 'freebsd/stable/10' into hardened/10/aslr