std::vec: correct .sort()'s doc-string and add some
examples/clarification to others.
std::vec: clarify & examplify more docs.
Remove out of date test

The associated issue has been closed for 2 years!
Method-ify CStore
auto merge of #11146 : sfackler/rust/cleanup, r=alexcrichton

I also deleted a test which has apparently not been needed for a very long time.
auto merge of #10965 : alexcrichton/rust/libgreen, r=brson

This pull request extracts all scheduling functionality from libstd, moving it into its own separate crates. The new libnative and libgreen will be the new way in which 1:1 and M:N scheduling is implemented. The standard library still requires an interface to the runtime, however, (think of things like `std::comm` and `io::println`). The interface is now defined by the `Runtime` trait inside of `std::rt`.

The booting process is now that libgreen defines the start lang-item and that's it. I want to extend this soon to have libnative also have a "start lang item" but also allow libgreen and libnative to be linked together in the same process. For now though, only libgreen can be used to start a program (unless you define the start lang item yourself). Again though, I want to change this soon, I just figured that this pull request is large enough as-is.

This certainly wasn't a smooth transition, certain functionality has no equivalent in this new separation, and some functionality is now better enabled through this new system. I did my best to separate all of the commits by topic and keep things fairly bite-sized, although are indeed larger than others.

As a note, this is currently rebased on top of my `std::comm` rewrite (or at least an old copy of it), but none of those commits need reviewing (that will all happen in another pull request).
auto merge of #11127 : huonw/rust/vec-docs, r=alexcrichton
Remove std::{either, util::Void}