[GEOT-4501] Allow granule based readers to expose their inner structure
Have ImageMosaic implement the structured coverage grid reader interface, support file harvesting, handle multiple coverages and properly support a mosaic of NetCDF. Also, have the module support oracle data stores as a backend
Improve the NG raster API, add support in NetCDF readers for multiple coverages, read only structured grid coverage reader support, high performance ND indexing
minor fixes to headers and javadocs

Signed-off-by: Jody Garnett <jody.garnett@gmail.com>