mozilla/rust — pull request #11939 by JeremyLetang (2014-01-30 20:09:56+00:00)
Title: move concurrent stuff from libextra to libsync

This time everything should be okay, No break due to a failed merge or rebase...

Sorry for the abuse of pull request.

So this move extra::sync, extra::arc, extra::future, extra::comm and extra::task_pool to libsync.