Added Delete(ControlMeasure *) method. Fixed bugs related to network...

Added Delete(ControlMeasure *) method.  Fixed bugs related to network notification of measure addition and deletion.  Added some documentation.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@1822 41f8697f-d340-4b68-9986-7bafba869bb8