Address Regex Memory Bloat in Long Running Applications

[iwillspeak]

Thread-local scratch space is only clearered when the regex is disposed. If regexes are used on the threadpool you can end up with quite a lot of memory usage quite quickly.

We could solve this by exposing the ability to clone the regex for each match.

[iwillspeak]

This is going to need a clone function adding to the regex batteries crate and exposing for FFI.

[iwillspeak]

Cloning might not be required given the fix upstream in rust-lang/regex#362. Addressing that with iwillspeak/IronRure-Batteries#18.