Heatmap scalability

The heatmap plugin is not very scalable at the moment. For millions few data points, the map is "laggy" when moving the maps around (at a reasonable zoom level, when most of the data points are hidden).

From what I've investigated, it comes from the fact the, when the _redraw function is called, the code iterates over all data points to check if it is or not in the bounds of the map being shown.
It seems very inefficient since there exists data structure such as R-Tree that can efficiently retrieve the data points inside a box.

Now it seems that the Leaftlet.heat plugin is not maintained anymore (as noted in #1282 ). As far as I can tell, there is only the .min.js file on this repository, what are the plans for this plugin?
Host it completely on this organization so it can be modified and maintained?

For the problem of the performances, I wrote a quick POC using rbush and it improves the performance when we zoom on a specific area (and fewer points are actually shown on the map). I can contribute to this issue if necessary.

首先定位 heatmap 插件的压缩 JavaScript 及其 _redraw 路径，然后检查已报告的 rbush proof of concept 以及围绕 Leaflet.heat 的维护问题。完成的要求是确定一个经过同意的插件维护范围，并证明 heatmap 在渲染数百万个点时性能更好。