Add more options to buffering
Refactor styled buffering to work with geos < 3.2
Add more detailed description about styled buffering
Add short example for style buffering
Change parameter type of buffer for consistency with parellel_offset
Update manual for styled buffering
Updates to manual and change log for 1.2.18.
Add enum style classes for cap and join styles
Add missing cap and join style imports
Use join style class for parallel_offset operation
Merge branch 'buffer-with-style' of git://github.com/ahojnnes/Shapely into ahojnnes-buffer-with-style

Conflicts:
	shapely/geometry/__init__.py

Make enum members lowercase as in PEP 435 examples.
Use new enums from #55.