Fixes the order in which FutureVar and return completions are made.
Fixes the order in which FutureVar and return completions are made.

This caused a pretty bad and subtle bug in the asynchttpserver.
As far as I can understand, the fact that the returned future was
being completed first meant that the underlying async procedure
could continue running and thus clean() the FutureVar
and request new data. The control then went back and the
FutureVar was completed again causing an error.

dom96/Nim,russpowers/Nim,russpowers/Nim,tulayang/Nim,russpowers/Nim,russpowers/Nim,dom96/Nim,dom96/Nim,tulayang/Nim,dom96/Nim,russpowers/Nim,dom96/Nim,tulayang/Nim,dom96/Nim,tulayang/Nim,tulayang/Nim,tulayang/Nim,russpowers/Nim,dom96/Nim,russpowers/Nim