WIP -- trait resolution branch

Conflicts:
	src/librustc/lint/builtin.rs
	src/librustc/metadata/common.rs
	src/librustc/metadata/encoder.rs
	src/librustc/middle/astencode.rs
	src/librustc/middle/dead.rs
	src/librustc/middle/save/mod.rs
	src/librustc/middle/trans/callee.rs
	src/librustc/middle/trans/common.rs
	src/librustc/middle/trans/expr.rs
	src/librustc/middle/trans/meth.rs
	src/librustc/middle/ty.rs
	src/librustc/middle/ty_fold.rs
	src/librustc/middle/typeck/check/method.rs
	src/librustc/middle/typeck/check/mod.rs
	src/librustc/middle/typeck/check/regionck.rs
	src/librustc/middle/typeck/check/vtable.rs
	src/librustc/middle/typeck/check/writeback.rs
	src/librustc/middle/typeck/coherence/mod.rs
	src/librustc/middle/typeck/infer/coercion.rs