0.0.7

• support sub zfs filesystems (datasets)
• optional use sudo when execute zfs commands
  • necessary under linux when running as non root
  • needs sudo rules (see doc/etc/sudoers.d/zfs-snap-diff)
  • start zfs-snap-diff with '-use-sudo'
• new view for server messages

all commits from 0.0.6...0.0.7