Merge branch 'master' of https://github.com/mozilla/rust into try-merge

Conflicts:
	src/librustc/session/config.rs
	src/librustc_back/target/mod.rs
	src/librustc_trans/trans/context.rs
	src/librustc_trans/trans/mod.rs
	src/librustrt/local_ptr.rs
	src/librustrt/mutex.rs
	src/librustrt/thread.rs
	src/librustrt/thread_local_storage.rs
	src/libstd/os.rs
	src/libstd/rt/backtrace.rs
	src/libstd/rt/mod.rs
	src/libstd/rt/unwind.rs
	src/libsyntax/abi.rs