dotcloud/docker — pull request #5772 by unclejack (2014-05-13 12:41:40+00:00)
Title: process directories in parallel in ChangesDirs

This PR lowers the total time spent in ChangesDirs to half during a commit. ChangesDirs is called twice during a commit and this saves about 2 seconds for `make build` when only the final ADD has to be run during the build.