rustc: Update both versions of the compiler

  rustc: 1.2.0 -> 1.3.0
  rustcMaster: 2015-09-05 -> 2015-09-21

This also removes the llvm bundling which reduced immediate the closure size
by ~50MB. It also tries to reduce some of the superfluous dependencies
to help reduce the number of potential rebuilds (namely removing git).