Stop using @ExtCtxt
Remove unecessary extern "Rust" specifiers
Stop passing duplicate parameters in expand
rust.md : update crate attributes.

#[ author = "Jane Doe" ]; raises "warning: unknown crate attribute"
Add /doc/{green,native} to .gitignore
Add method .as_mut_slice() to MutableVector

This method is primarily intended to allow for converting a [T, ..N] to
a &mut [T].
Add /doc/{rustc,syntax} to .gitignore
Rename pkgid variables
Rename PkgId to CrateId
Rename uses of PkgId to CrateId in librustpkg
Update Docs to use crateid
Register new snapshots.
Actually block in a windows cvar

Turns out with an argument of 0 the function always returns immediately!

Closes #11003
Update llvm.
auto merge of #11181 : luqmana/rust/up-llvm, r=alexcrichton

No longer need to handle GNUEABIHF and hard floats since LLVM should now choose the right default. Fixes #11164.
rustdoc: only filter lines starting with '# ' from the shown code.

Currently any line starting with `#` is filtered from the output,
including line like `#[deriving]`; this patch makes it so lines are only
filtered when followed by a space similar to the current behaviour of
the tutorial/manual tester.
rustdoc: Unify the handling of the hidden example lines.
Make ast_fold take &mut self
Start passing around &mut ExtCtxt
Remove @muts from ExtCtxt