Upstreaming filenotify-recursive

[Jethro Kuan <jethrokuan95@gmail.com>]

Hello!

I'd recently written a package that wraps filenotify somewhat
transparently, providing a similar API to the built-in filenotify but it
watches the directory recursively, spawning and destroying watchers as
appropriately. It was suggested to me that this could be upstreamed to
Emacs. The code is here:

https://github.com/jethrokuan/filenotify-recursive

I don't mind doing the work in getting this upstreamed, but I have a few
concerns. Because of how filenotify works, filenotify-recursive uses own
its global variables to keep track of the descriptors. It's best to
think of a way to merge this functionality into filenotify.el itself,
but I can't think of a good way right now. I'm open to any thoughts and
suggestions here.

Jethro