New vnc screenshot valkyrie and minor fixes

- VNC screenshot added. Requires the vncsnapshot binary. This can be
  installed in Ubuntu. For OSX you'll need to patch or use homebrew.

- Running valkyries grouped into a single fucntion in services.py
  controller. This will mean adding new ones may be fairly easy for
  running aginast services. Not sure about hosts, accounts, etc.

- Minor cleanup of log, shodanhq and db.py.sample