core:rt:: Rename LocalServices to Task
core::rt: Add Local trait
core::rt: Store Task as a ~ pointer
rt: Rename rust_initialize_global_state to rust_initialize_rt_tls_key
core::rt: Move some TLS functions from local_sched to local_ptr
core::rt: Move more TLS functionality into local_ptr
core::rt: Make local_sched a wrapper around Local
core::rt: Convert users of local_sched to Local trait
core::rt: Remove local_sched module
core::rt: Implement Local for Task