Added reference to gdal_data folder.
Merge branch 'master' of https://github.com/gwaldron/osgearth
WIP: saving status of work re controls and iOS
Merge branch 'master' of https://github.com/gwaldron/osgearth

Conflicts:
	src/osgEarthUtil/Controls.cpp
More work enabling controls on iOS.
Finishing first cut of Controls functionality on iOS.