MeasureTool.h: 2011-09-20 Steven Lambright - Added some abstraction, fixed...

MeasureTool.h: 2011-09-20 Steven Lambright - Added some abstraction, fixed problems with segmented line and rectangle. Fixes #218. 
RubberBandTool.h: 2011-09-20 Steven Lambright - Segmented lines now have updates while the user is still drawing them instead of just a complete state. 

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@3268 41f8697f-d340-4b68-9986-7bafba869bb8