dl-snapshot: be more forgiving to triples
bug fix for oh-my-zsh
auto merge of #920 : CMGS/cargo/master, r=eerden

when I use this script in oh-my-zsh, it will raise an error, so I modified it..
auto merge of #913 : jmesmon/cargo/forgive-wierd-triples, r=alexcrichton
fix capitalization in build script docs
auto merge of #922 : steveklabnik/cargo/patch-1, r=alexcrichton
Update to newest Rust
auto merge of #956 : jakub-/cargo/newest-rust, r=alexcrichton
Fix the root output directory when cleaning examples

This forgot to take into account the logic from some other locations, so I added
a helper method!

Closes #912