auto merge of #1036 : brson/cargo/flakeywindows, r=alexcrichton
Bump rustc version
auto merge of #1039 : alexcrichton/cargo/update-rust, r=alexcrichton
Add support for a custom arguments list when running main.
auto merge of #1042 : cgaebel/cargo/execute-main-with-custom-args, r=alexcrichton