Iterator documentation fixes

Fixes two typos and one incorrect description.
Alter rust.css to make the documentation look more appealing
update jemalloc to 3.4.0
Visitor refactoring: Step 1, couple (Env, vt<Env>) together in a tuple.
Fix linebreak and whitespace issues to placate make tidy.
auto merge of #7073 : influenza/rust/iterator-doc-fixes, r=catamorphism

This commit fixes two typos and an incorrect description.
Properly translate calls to default methods in a number of cases. Closes #4350.
Drop some dead method handling code.
Fix a lot of the handling of default methods and type parameters. Closes #4099, #4102.
Merge branch 'moz-incoming' into fsk-visitor-refactoring
Fix a test-predicated use of the visit.rs api.
auto merge of #7084 : pnkfelix/rust/fsk-visitor-refactoring, r=pnkfelix

This step 1 in my plan for issue #7081: Refactor visit.rs with a `@Visitor` trait.
auto merge of #7077 : SiegeLord/rust/new_css, r=pnkfelix

I was making documentation for my own little Rust project, and I was somewhat unhappy with how the documentation looked. While many of the issues are endemic to how rustdoc generates its output, you can get pretty far in making the documentation readable by using a better CSS style.

This commit alters the CSS style used in Rust's documentation in order to make the various sections stand out more. You can see an example of its usage in my own project's documentation: http://siegelord.github.io/RustGnuplot/#implementation-for-figureself-where-self. I showed it to some people on IRC and they suggested that I make a pull request here. I tested it on the only browser that matters, but also Chrome and Opera.
auto merge of #7091 : msullivan/rust/default-methods, r=graydon

r? @nikomatsakis
std: make all strings Equiv-alent to each other, generalise Path.push_many to take any type of string.
Use @str instead of @~str in libsyntax and librustc. Fixes #5048.

This almost removes the StringRef wrapper, since all strings are
Equiv-alent now. Removes a lot of `/* bad */ copy *`'s, and converts
several things to be &'static str (the lint table and the intrinsics
table).

There are many instances of .to_managed(), unfortunately.
rustdoc: fix tests for @~str -> @str change.
Prototyped a dynamic library facility interface
rustc: fix test failures after rebase.
make util::NonCopyable a unit struct instead of a struct with a unit