Phobos v2 asynchronous IO

[IGotD-]

Is there any planning or work to move Phobos towards natively 
asynchronous IO? Right now most IO is synchronous like you would 
expect from an API from the 90s. Time has moved on asynchronous 
IO should be standard.

This means that everything should be asynchronous, file streams, 
networking, anything that streams as standard. If this is 
implemented then we also can look into adding native asynchronous 
task support (like C# async).