Updated release notes for 0.11.0
Update to 0.11.0
rustdoc: s/nil/unit/ internally.

Quick poll on IRC suggested that unit was the preferred name for ().
Merge remote-tracking branch 'origin/master' into 0.11.0-release

Conflicts:
	src/libstd/lib.rs
Merge remote-tracking branch 'origin/master' into 0.11.0-release

Conflicts:
	RELEASES.txt
core: add a primitive page for `()`.
auto merge of #15343 : alexcrichton/rust/0.11.0-release, r=brson
auto merge of #15321 : huonw/rust/nil-prim, r=alexcrichton

This adds a primitive page for () like http://doc.rust-lang.org/master/std/uint/primitive.uint.html .

I would prefer the modules to be `std::tuple::unit`, but rustdoc only searches at the top level (filed as #15320).