Moved .sleep() to Timer.
Add assert_once_ever macro. Close #7748. (fixme cf #8472)
Added home_for_io_with_sched variant. Temporarily making IO unkillable.
small cleanups in task/spawn.rs
Refactor type combining to use default methods.  Woohoo!

This commit removes the "super_*" functions from
typeck::infer::combine, and adds them as default methods on the
Combine trait instead, making it possible to remove a lot of
boilerplate from the various impls of Combine.

I've been wanting to do this for over a year.  In fact, it was my
original motivation for default methods!

It might be possible to tighten things up even more, but this is the
bulk of it.
Don't fail in port.try_recv() the second time. Close #7800.
Only bug on self-not-mapped-to-def if no previous errors were present. Close #6642.
Make json::to_xxx(&Json) fns Json::to_xxx(&self)

to_str, to_pretty_str, to_writer, and to_pretty_writer were at the top
level of extra::json, this moves them into an impl for Json to match
with what's been done for the rest of libextra and libstd.
On Windows, use g++ for linking, instead of gcc.
This is required in order to produce linked modules that perform correct registration of unwind tables.
Un-disable stack unwinding on Windows.
Emit unwind info in rustrt assembly files on Windows.
Compile via external assembler on Windows.
Enabled tests.
Cleanup assembly source.
debuginfo: Big cleanup refactoring and support for foreign_item_fn.
debuginfo: Improved handling of function preludes.
doc: add range iterators in the for loop section
Don't ICE if an argument in a default method doesn't have a name. Closes #8417.
Add `self` to the ast_map for provided methods. Closes #8010.
auto merge of #8669 : lkuper/rust/infer-refactor, r=nikomatsakis

This commit removes the "super_*" functions from
typeck::infer::combine, and adds them as default methods on the
Combine trait instead, making it possible to remove a lot of
boilerplate from the various impls of Combine.

I've been wanting to do this for over a year.  In fact, it was my
original motivation for default methods!

It might be possible to tighten things up even more, but this is the
bulk of it.