several plugins for v4

[Vijith Assar]

I've recently updated several plugins to work with D3 version 4:

- d3-textwrap: line wrapping for long text strings (example)

- d3-history: enable deep linking to specific interface states based on events (example)

- d3-parent: inverted selection that searches up the DOM tree (example)

- d3-rect: draw rectangles with path strings instead of rect elements (example)

[Mike Bostock]

I took the liberty of adding your plugins to the wiki, as well as re-organizing the page to call out the plugins that have been updated to v4:

https://github.com/d3/d3/wiki/Plugins

Regarding d3-rect, I’m not sure if this is useful to you, but d3-path implements path.rect from the CanvasPathMethods API. This means that you can write code that takes a CanvasPathMethods instance as input, and can either render directly to a canvas given a CanvasRenderingContext2D or render to SVG using d3-path. See the d3-shape symbol implementations for examples:

https://github.com/d3/d3-shape/tree/master/src/symbol