Bezier

- Added [`Curve.locate()`](http://bezier.readthedocs.io/en/0.2.1/reference/bezier.curve.htmlbezier.curve.Curve.locate) and [`_curve_helpers.newton_refine()`](http://bezier.readthedocs.io/en/0.2.1/algorithm-helpers.htmlbezier._curve_helpers.newton_refine) helper
- Adding optional `color` to [`Surface.plot()`](http://bezier.readthedocs.io/en/0.2.1/reference/bezier.surface.htmlbezier.surface.Surface.plot)
- Adding [`Surface.elevate()`](http://bezier.readthedocs.io/en/0.2.1/reference/bezier.surface.htmlbezier.surface.Surface.elevate) for degree elevation
- Fixing nodes defining the [self-intersecting curve](http://bezier.readthedocs.io/en/0.2.1/curve-curve-intersection.htmldetecting-self-intersections) in `curve-curve-intersection` (no code in `bezier` was broken / fixed, just "bad" docs)
- Allow wiggle outside of `[0, 1]` when intersecting linearizations in `from_linearized()`
- Collapsing almost-same parameter values in `intersect_one_round()` (via `from_linearized()`). Previously checked for bitwise equality and relied on checking values at the boundary of a subdivided interval
- Adding non-public `bezier._plot_helpers` module

- **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`

Changes:
- Adding [`Curve.elevate()`](http://bezier.readthedocs.io/en/0.1.1/reference/bezier.curve.htmlbezier.curve.Curve.elevate) for degree elevation
- Upgrading curve-curve intersection algorithm to ignore parallel line segments that don't meet (rather than throwing `NotImplementedError`)
- Making [`segment_intersection()`](http://bezier.readthedocs.io/en/0.1.1/reference/bezier.curve.htmlbezier._intersection_helpers.segment_intersection) return a `success` bool instead of raising `NotImplementedError` on failure
- Updating docs for [`newton_refine()`](http://bezier.readthedocs.io/en/0.1.1/reference/bezier.curve.htmlbezier._intersection_helpers.newton_refine) with two examples and making [`parallel_different()`](http://bezier.readthedocs.io/en/0.1.1/reference/bezier.curve.htmlbezier._intersection_helpers.parallel_different) a publicly documented function (as a partner to `segment_intersection()`)
- Adding some more examples / failures to `curve-curve-intersection` [doc](http://bezier.readthedocs.io/en/0.1.1/curve-curve-intersection.html)

Primary changes since previous release ([`0.0.1`](https://pypi.org/project/bezier/0.0.1/)) are related to curve-curve intersection. See [the intersection docs](http://bezier.readthedocs.io/en/0.1.0/curve-curve-intersection.html) for examples and more information.