rt: don't save and restore xmm/regs in __morestack.
gitignore: Add build/ subdirectory
vec: add an external iterator
auto merge of #5919 : catamorphism/rust/gitignore, r=catamorphism
Errors with the same span print the span once
auto merge of #5923 : thestinger/rust/iterator, r=graydon
sketch: Make rust sketch barf output prettier
Small typos, year date and URL of the fbuild system for reference.
libcore: add an EnumerateIterator, like Python's `enumerate`.
auto merge of #5927 : huonw/rust/core-enumerate-iterator, r=thestinger
libcore: make spawn_supervised documentation reflect its behaviour.
Implement bitwise operator traits for ints and uints
auto merge of #5928 : huonw/rust/core-task-spawn-supervised-doc, r=thestinger

The doc-comment didn't reflect the [tasks tutorial](http://static.rust-lang.org/doc/tutorial-tasks.html#failure-modes), or how it works in practice.
auto merge of #5929 : intgr/rust/sketch_output, r=thestinger

The last line of any command output should always have a newline. Also fixed typo, "on on"

summary of 25 test runs: 4563 passed; 0 failed; 344 ignored
core: add a str iterator
auto merge of #5930 : osaut/rust/master, r=thestinger

Just small typos I found during my study of rust sources. 
I have added the fbuild URL for reader's convenience.
Add #[inline(always)] to each operator method
core: io: the read_until function checks bytes not chars, so type should reflect that.
auto merge of #5932 : huonw/rust/core-str-iterator, r=thestinger
auto merge of #5933 : huonw/rust/core-read-until-byte, r=thestinger

`read_until` is just doing a bytewise comparison. This means the following program prints `xyå12`, not `xy`, which it should if it was actually checking chars.

```rust
fn main() {
    do io::with_str_reader("xyå12") |r| {
        io::println(r.read_until('å', false));
    }
}
```

This patch makes the type of read_until match what it is actually doing.