Reverse the order of the projection coordinates of grids from [x, y] to [y, x]

[mauzey1]

Resolves #996

Example from the file generated by examples/python/example_06_complex_grid.py.

        double latitude(y, x) ;
                latitude:standard_name = "latitude" ;
                latitude:long_name = "latitude" ;
                latitude:units = "degrees_north" ;
                latitude:missing_value = 1.e+20 ;
                latitude:_FillValue = 1.e+20 ;
                latitude:bounds = "vertices_latitude" ;
        double longitude(y, x) ;
                longitude:standard_name = "longitude" ;
                longitude:long_name = "longitude" ;
                longitude:units = "degrees_east" ;
                longitude:missing_value = 1.e+20 ;
                longitude:_FillValue = 1.e+20 ;
                longitude:bounds = "vertices_longitude" ;
        double vertices_latitude(y, x, vertices) ;
                vertices_latitude:units = "degrees_north" ;
                vertices_latitude:missing_value = 1.e+20 ;
                vertices_latitude:_FillValue = 1.e+20 ;
        double vertices_longitude(y, x, vertices) ;
                vertices_longitude:units = "degrees_east" ;
                vertices_longitude:missing_value = 1.e+20 ;
                vertices_longitude:_FillValue = 1.e+20 ;
        float hfls(time, y, x) ;
                hfls:standard_name = "surface_upward_latent_heat_flux" ;
                hfls:long_name = "Surface Upward Latent Heat Flux" ;
                hfls:units = "W m-2" ;
                hfls:cell_methods = "area: time: mean" ;
                hfls:missing_value = 1.e+20f ;
                hfls:_FillValue = 1.e+20f ;
                hfls:cell_measures = "area: areacella" ;
                hfls:grid_mapping = "lambert_conformal_conic" ;
                hfls:coordinates = "latitude longitude" ;

[durack1]

@mauzey1 wonderful that output looks great - I am hoping these other examples, the other CRS targets also check out ok?

[taylor13]

Looks good to me. Thank!
Karl