Fix up deregister image, add doc strings
Fix up deregister image, add doc strings

nagyistoce/eutester,nephomaniac/eutester,nephomaniac/nephoria,tbeckham/eutester,nagyistoce/eutester,shaon/eutester,tbeckham/eutester,tbeckham/eutester,sjones4/eutester,tbeckham/eutester,shaon/eutester,sjones4/eutester,nephomaniac/eutester,shaon/eutester,nagyistoce/eutester,nephomaniac/nephoria,shaon/eutester,sjones4/eutester,sjones4/eutester,nephomaniac/eutester,nagyistoce/eutester