orog.fd - Remove binary output option and logic for reduced grid. (#949)

In the FV3 era, the 'orog' files are tiled NetCDF. Remove the binary and GRIB1
output options, which are no longer used.

Remove logic for the 'reduced' gaussian grid, which is left over from 
the spectral GFS era.

Includes some other minor cleanup of obsolete code.

Fixes #940.