[dmd-concurrency] draft 5

[Andrei Alexandrescu]

Apparently I can't convince Brad that I'm not spamming - my attachments 
keep on being delayed through moderation because they're too big.

I uploaded draft 5 here:

www.erdani.com/d/fragment.preview.pdf

Again: Don't re-read what you've already read, move forward. Feedback
would be appreciated. Sean, Walter, please let me know quickly if you
see any major implementation issues.


Thanks,

Andrei