wip: add winrt implementation

[geovie]

Todo:

• write characteristic
• Central events
• Adapter events
• proper error handling
  ...

[qdot]

As I am badly in need of a Win10 UWP bluetooth library for rust, I'm going to see about getting a few things patched up here on my fork at https://github.com/qdot/rumble (I'll maintain issues there as this patch has been sitting here forever anyways). Good news is, this patch still compiles after fixing a couple of syntax errors and missing trait methods! UWP finds devices just fine, but there's a lot of eccentricities like uuid byte ordering being different than linux (which is fine, some libraries network order, some don't), discover_characteristics not storing characteristics off to be retrieved through the characteristics() call (which may just be due to the patch being 18 months old), and what not, as well as still needing device events, writing characteristic values, etc.

I'll submit my patches when done. I'm a little dubious on how good of a solution rumble is going to be without some API redesign, as this really feels like trying to shoehorn everything into Bluez's model, which ain't great. That said, I totally respect what's been done so far and I'll definitely take "mostly done" over "starting from scratch" at the moment. :)