fix Antarctica for 'geos' projection, use npy.sum not python built-in,  refine checks for bad polygons to avoid 'Bus errors' in ctypes libgeos interface.
fix Antarctica for 'geos' projection, use npy.sum not python built-in, 
refine checks for bad polygons to avoid 'Bus errors' in ctypes libgeos
interface.

svn path=/trunk/toolkits/basemap-testing/; revision=4137

guziy/basemap,guziy/basemap,matplotlib/basemap,matplotlib/basemap