Moved SampleShift and LineShift out of the ControlMeasureLogData class and...

Moved SampleShift and LineShift out of the ControlMeasureLogData class and into ControlMeasure, where they are now calculated as difference between the Sample/Line and the Apriori.  Consequently, ControlMeasure can also calculate the PixelShift as the Euclidean distance shifted.  By allowing programs to report on all three of these values, this change fixes #159.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@2804 41f8697f-d340-4b68-9986-7bafba869bb8