auto merge of #16664 : aturon/rust/stabilize-option-result, r=alexcrichton

Per API meeting

  https://github.com/rust-lang/meeting-minutes/blob/master/Meeting-API-review-2014-08-13.md

# Changes to `core::option`

Most of the module is marked as stable or unstable; most of the unstable items are awaiting resolution of conventions issues.

However, a few methods have been deprecated, either due to lack of use or redundancy:

* `take_unwrap`, `get_ref` and `get_mut_ref` (redundant, and we prefer for this functionality to go through an explicit .unwrap)
* `filtered` and `while`
* `mutate` and `mutate_or_set`
* `collect`: this functionality is being moved to a new `FromIterator` impl.

# Changes to `core::result`

Most of the module is marked as stable or unstable; most of the unstable items are awaiting resolution of conventions issues.

* `collect`: this functionality is being moved to a new `FromIterator` impl.
* `fold_` is deprecated due to lack of use
* Several methods found in `core::option` are added here, including `iter`, `as_slice`, and variants.

Due to deprecations, this is a:

[breaking-change]

diff --cc src/libcollections/dlist.rs
Simple merge

diff --cc src/libcollections/ringbuf.rs
Simple merge

diff --cc src/libcollections/treemap.rs
Simple merge

diff --cc src/libcore/cell.rs
Simple merge

diff --cc src/libcore/iter.rs
Simple merge

diff --cc src/libgreen/task.rs
Simple merge

diff --cc src/libnative/task.rs
Simple merge

diff --cc src/librustc/driver/driver.rs
Simple merge

diff --cc src/librustdoc/clean/inline.rs
Simple merge

diff --cc src/librustdoc/clean/mod.rs
Simple merge

diff --cc src/librustdoc/html/render.rs
Simple merge

diff --cc src/librustrt/task.rs
Simple merge

diff --cc src/librustuv/timeout.rs
Simple merge

diff --cc src/libsync/raw.rs
Simple merge