We disable new warnings that are triggered in depot_tools to pylintrc.
So the lint output before & after this CL are mostly unchanged.  The
repos checked: depot_tools, src, and build.

Also update astroid to 1.4.9 and drop logilab.common as needed.

Bug: 863669
Change-Id: Ib602560c1bcad5a9e8b6ca731d9465f43220f044
Reviewed-on: https://chromium-review.googlesource.com/1137382Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>