auto merge of #18070 : alexcrichton/rust/spring-cleaning, r=aturon

This is a large spring-cleaning commit now that the 0.12.0 release has passed removing an amount of deprecated functionality. This removes a number of deprecated crates (all still available as cargo packages in the rust-lang organization) as well as a slew of deprecated functions. All `#[crate_id]` support has also been removed.

I tried to avoid anything that was recently deprecated, but I may have missed something! The major pain points of this commit is the fact that rustc/syntax have `#[allow(deprecated)]`, but I've removed that annotation so moving forward they should be cleaned up as we go.

diff --cc src/librustc/middle/typeck/check/mod.rs
Simple merge

diff --cc src/libstd/num/f32.rs
Simple merge

diff --cc src/libstd/num/f64.rs
Simple merge

diff --cc src/libsyntax/print/pprust.rs
Simple merge