Added a few image data types for RGPS.
Implemented measures2netcdf tool to convert gridded RGPS MEaSUREs products into netCDF files.
Minor changes for issues that Ed found with the products.
Minor changes to make sure that our netCDF file are CF compliant. Otherwise, they did not work with ncdump, panoply and friends.
Updated the CSV file generation.
Push latest changes in RGPS.
Merge branch 'rgps'

Conflicts:
	src/asf_meta/asf_meta.h
	src/libasf_export/asf_export.h
	src/libasf_export/export_netcdf.c
	src/libasf_import/import_uavsar.c
	src/measures2csv/measures2csv.c