auto merge of #285 : alexcrichton/cargo/fix-cargo-doc, r=wycats
authorbors <bors@rust-lang.org>
Tue, 29 Jul 2014 21:14:29 +0000 (21:14 +0000)
committerbors <bors@rust-lang.org>
Tue, 29 Jul 2014 21:14:29 +0000 (21:14 +0000)
The existing rustdoc behavior for working with an already-present directory is
good enough, so there's no need for cargo to help out by blowing things away.
This also makes the copy-back portion easier by just not having it.

Closes #284


Trivial merge