This change should have no user-impact. Renamed 'iString' to 'IString', added...

This change should have no user-impact. Renamed 'iString' to 'IString', added some QString-related functionality, and updated the Isis coding standards related to strings. Fixes #1051.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@4761 41f8697f-d340-4b68-9986-7bafba869bb8