glsl checks, ocean fix, geodata
Merge branch 'topic-fallback' of github.com:gwaldron/osgearth into topic-fallback
Merge branch 'topic-fallback' of github.com:gwaldron/osgearth into topic-fallback
Merge branch 'topic-fallback' of github.com:gwaldron/osgearth into topic-fallback
Elevation: add 'mapped resolution' heightfield generation