- **Primary feature**: [`Surface.intersect()`](http://bezier.readthedocs.io/en/0.2.0/reference/bezier.surface.htmlbezier.surface.Surface.intersect) added
- To support intersection, needed [`CurvedPolygon`](http://bezier.readthedocs.io/en/0.2.0/reference/bezier.curved_polygon.htmlbezier.curved_polygon.CurvedPolygon), i.e. an object defined only by its curved sides (whereas a `Surface` may have interior control points)
- [`Curve.specialize`](http://bezier.readthedocs.io/en/0.2.0/reference/bezier.curve.htmlbezier.curve.Curve.specialize) for chopping a `Curve` at arbitrary parameter values (this is also used in surface-surface intersection)
- Added images to most documented functions and methods to illustrate the concept at hand. For example
[`classify_intersection`](http://bezier.readthedocs.io/en/0.2.0/algorithm-helpers.htmlbezier._surface_helpers.classify_intersection) has **seven** images to enumerate all of the possible cases covered in the algorithm.
- Added [`Surface.locate()`](http://bezier.readthedocs.io/en/0.2.0/reference/bezier.surface.htmlbezier.surface.Surface.locate), made possible by [`newton_refine`](http://bezier.readthedocs.io/en/0.2.0/algorithm-helpers.htmlbezier._surface_helpers.newton_refine)
- Added [Algorithm Helpers](http://bezier.readthedocs.io/en/0.2.0/algorithm-helpers.html) doc to try to explain some of the core algorithms at work (not all are documented yet). Some of this content was previously documented in the `bezier.curve` module, but was moved. Since, documentation has been added for `get_curvature`, `newton_refine` (for surfaces), `classify_intersection` (to determine how two curves interact while intersecting) and for some helper classes.
- Added `Surface.base_x`, `Surface.base_y` and `Surface.width` [properties](http://bezier.readthedocs.io/en/0.2.0/reference/bezier.surface.htmlbezier.surface.Surface.width) to allow tracking a sub-surface during the subdivision process (this is an analogue to the `Curve.start` and `Curve.end` [properties](http://bezier.readthedocs.io/en/0.2.0/reference/bezier.curve.htmlbezier.curve.Curve.start))
- Added `Curve.edge_index`, `Curve.next_edge` and `Curve.previous_edge` [properties](http://bezier.readthedocs.io/en/0.2.0/reference/bezier.curve.htmlbezier.curve.Curve.edge_index) to allow tracking when curves are actually the sides of a `Surface`