Move to new libcore

[bharrisau]

Work is progressing on splitting up libstd (rust-lang/rust#13851). This issues is to track that change.

[farcaller]

rust.patch is currently broken due to this issue (so are travis tests)

[farcaller]

Frozen the libstd commit on rust-lang/rust@2dcbad5 for now.

[bharrisau]

Hopefully we won't need the patch. libcore should have everything we need (and build as a rlib out of the box). I'll have a play tonight/over the weekend.

[farcaller]

One thing to check is if #[deriving(Eq)] still works.

[bharrisau]

Haven't actually check it. But the libcore prelude exports Eq https://github.com/mozilla/rust/blob/master/src/libcore/prelude.rs

[farcaller]

Well, another round of renaming things then 🔃

[farcaller]

Initial move done in #35.

[farcaller]

Done. There's one TODO left in https://github.com/hackndev/zinc/blob/master/src/main.rs#L54, should be cleaned up when fixed in rust.