The default darwin build added a je_ prefix to all exported symbols, and
that broke downstream consumers that were not expecting the prefix, like
mariadb.
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).
