Auto merge of #2871 - QuiltOS:doc-build-deps, r=alexcrichton
authorbors <bors@rust-lang.org>
Mon, 8 Aug 2016 17:37:17 +0000 (10:37 -0700)
committerGitHub <noreply@github.com>
Mon, 8 Aug 2016 17:37:17 +0000 (10:37 -0700)
Better rational for build-dependencies and other kinds being disjoint.

The old reason was bad because nothing prevents normal dependencies from
being built before the build script.


Trivial merge