Backporting Tango runtime enhancements to druntime

[mta`chrono]

We could also rewrite tango.core.Thread so that it extends core.thread. 
But keep the old interface/API. Some of the tango special feature might 
be wrapped in this case.

In my mind it's more important that tango.core.Atomic gets deprecated, 
because it doesn't work well on my maschine. I have outcommented nearly 
half of it to get it run at a minimum.


- mta`chrono