Test multipart input to unary_union.
Merge branch 'py3' of github.com:mwtoews/shapely into mwtoews-py3

Conflicts:
	shapely/tests/test_unary_union.py
Setuptools is back for good.

Following the recommendation at

https://python-packaging-user-guide.readthedocs.org/en/latest/current.html

Issues #40 and #56 are closed.
doc fixes:

* make html and htmlhelp depend on apigen
* really include CREDITS
* use absolute path in conf.py
* ignore auto generated doc files
Fix for #74.

At the start of affine_transform, return the geom if it is empty.
Add a list of development requirements.
Add descartes 1.0.1 to dev requirements.