Support for standalone ASIO

[Lssikkes]

I took a stab at porting the new ASIO backend to using the standalone ASIO library, but it was not as trivial as I'd hoped (posix::descriptor not available, nor is the timer, though there's an alternative using std::chrono). Are there any plans for standalone ASIO support?

[yangxingpping]

@Lssikkes I am also want something like this, can you share the code. or something describe in this
https://github.com/uNetworking/uSockets/issues/14

[Lssikkes]

@yangxingpping Unfortunately haven't tried further, currently just using libuv on windows and the native implementation on linux. Seems to work well enough.

[ghost]

Asio support is aimed at Boost users and eventually standard C++.