Shapely 1.2.18

I've tagged 1.2.18 and uploaded an sdist to PyPI. This release includes a couple of bug fixes, an update to the manual, and two new functions: shapely.ops.polygonize_full and shapely.ops.transform.

In other news I've made a milestone for Shapely 1.3, the major feature of which will be Mike Toews's work on supporting Python 3.