Setting thread priority

[Peter Alexander]

How do you set the priority of a thread, or otherwise control how much 
CPU time it gets?

It appears that std.thread had an answer for this, but it has been 
removed from Phobos by the looks of things.

On a side note, why is std.thread still in the online documentation if 
it was removed long ago? What's the point of having a tool to 
automatically generate documentation if we're going to have out of date 
docs anyway?