Bump version to 0.10-pre
Downgrade std back to 0.9 sice std inject is preventing the upgrade
rustc: Stop injecting crate version numbers in std_inject

The snapshot version injection is preventing us from upgrading to
0.10-pre, so I'm removing the version injection. Since our version-foo
is probably not good enough to allow multiple versions of these libs to
coexist side-by-side anyway, I think this will have minimal impact.
Downgrade green and rustuv to 0.9
auto merge of #11442 : brson/rust/0.10-pre, r=alexcrichton