Permit either foo/&self or foo<'self>
Update region inference for traits so that a method with
explicit self doesn't incorrectly cause the entire trait to
be tagged as being region-parameterized.
convert FnCtxt methods from @mut self to &self
Convert region parameterization to change defaults and handle
methods correctly
Improve error messages when illegal lifetimes are used
patch up pretty printing of things with both lifetime and type parameters