matplotlib Code

remove debug code

fix Antarctic polygon closing code

optimize code for closing Antarctica

Further speed improvements. For collections, now has faster ignoring
of elements that aren't provided, such as offsets. Paths now do not
even store the "default" codes array -- which is MOVETO followed by N
LINETOs. These are generated automatically by the iterators if no
codes array is provided. (Should also result in significant memory
savings for graphs with many points.)

use npy.sum, not built-in sum

add to list of projections that can't cross pole,
close Antarctica for all that don't.

fix tmerc example so it doesn't cross pole.

some projections should never cross pole.

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.

Speed up pcolor_demo.py "benchmark" initialization by a factor of 2.
Cache the automatically created path codes by their length.
pcolor, quadmesh etc. create lots of polylines of the same length, and
there is no need to create a new identical codes array each time.
(Definite speed improvement, incredible memory improvement).
Change the default behavior to create open paths (which don't result
in a memory copy). Fix places that were relying on
automatically-created closed paths to create closed paths themselves
(and thus avoiding a copy).