Add method to show and hide water surface

[GoogleCodeExporter]

Allow water surface to be hidden and shown programmatically, e.g.

ge.getOptions().setWaterSurfaceVisibility( false );

bool waterVisible = ge.getOptions().getWaterSurfaceVisibility();

A request to reopen issue 234 because suggested workaround removes terrain and 
we need to have altitude values and hidden water surface at the same time.

Original issue reported on code.google.com by numk...@gmail.com on 17 Jul 2012 at 1:52

[GoogleCodeExporter]

Trying to use the plugin to look at telemetry data from marine mammals which 
ins surface tracks (so want to look from above) and dive depths (so want to see 
those through below the surface). Unfortunately water surface effect rather 
blocks the view of dives and bathymetry. When using desktop Google Earth easy 
to turn it off but time control options too limited. Hoping to use plugin + API 
to create interface which offers more control over animating the visible time 
period but at the moment no option to turn off water surface and still keep 3D 
terrain/bathymetry :-(

Original comment by Clint.Bl...@gmail.com on 3 Oct 2013 at 4:47