more updates for 0.9
Fixes to drawmapboundary method.
fix minor bug when printing version number of required matplotlib
if resolution=None, no boundary data is needed (requested by Andrew Straw).
Updates for new set_aspect syntax
applied wx backend deprecation warning patch
support new API for postscript
use subprocess for usetex/ps externel dependencies
added patches to polar
do the transforms in backend_ps, dont pass them tp ps interpreter
