Complete refactoring, use hyper/h2 for connecting async.

[pimeys]

Just a test right now, DO NOT MERGE!

Are you still maintaining the library? I've been working on the past year finding out the best way of sending apple pushes, and now when hyper starts to support http2, we can solve lots of problems.

This is:

• Async and very fast
• Uses serde for serialization
• Support for cert and token auth
• rust-openssl 0.9
• No more solicit, hyper all the way
• The whole api needed to change

Now, I only tested the certificate part and this is the first ever working connection with hyper + h2 + alpn. Token part needs to be tested tomorrow. Also I should write more rustdoc. The alpn connector should stay out of this library, it's here because I needed one and there are no libraries providing it for hyper yet.

The question is should you merge this or should I create a new library such as tokio-apns2? I'm using rustls for alpn, I don't know does it work in OSX. I'm developing this with a Linux system.

What do you think?

[pimeys]

hyperium/hyper#304

[pimeys]

Works, but only tested with some hundreds of notifications, going to try this with some millions of notifications more before declaring stable. Should be MUCH faster than with solicit. :)