Provide mutable versions of exact_match and longest_match about treebitmap

[heroin-moose]

Yeah, I did the same xD
The problem is -- the author seems to be dead. We either need to fork this project or to call a necromancer.

[DRiKE]

I needed this as well for longest_match and came up with a very rudimentary version in https://github.com/zesplot/treebitmap/tree/longest_match_mut

It lacks tests and documentation, as I'm not sure whether this (i.e., repeating the immutable version of the function) is the desired way of doing it. @hroi , if you think it is, I can add tests+docs and create a pull request.

[pusateri]

Thanks for the mutable version of longest_match_mut(). I needed this too.

[hroi]

My thanks to whoever called the necromancer. I will try to get my shit together and stop neglecting this repo. If someone wants to help maintain it, please let me know!

[hroi]

Closed the wrong issue.

[heroin-moose]

Yay, @hroi has been revived ^_^