auto merge of #9577 : alexcrichton/rust/rustdoc, r=cmr

They're getting smaller each time though!

The highlight of this round is source files in documentation. Still trying to figure out the best syntax-highlighting solution.

diff --cc src/librustdoc/clean.rs
Simple merge

diff --cc src/librustdoc/html/render.rs
Simple merge

diff --cc src/librustdoc/rustdoc.rs
Simple merge