Started implementation of EllipsoidalGlobe. Minor corrections to Sector and ZeroElevationModel.

git-svn-id: http://worldwind31.arc.nasa.gov/svn/trunk@2462 822214bb-dcf7-4c8d-a767-17ae0fb20d88
Correction to EllipsoidalGlobe.

git-svn-id: http://worldwind31.arc.nasa.gov/svn/trunk@2463 822214bb-dcf7-4c8d-a767-17ae0fb20d88
Modified constructor creation pattern to be consistent. Corrected some minor mistakes in Location.

git-svn-id: http://worldwind31.arc.nasa.gov/svn/trunk@2464 822214bb-dcf7-4c8d-a767-17ae0fb20d88