Dump typedef info in `hh_client --show`

Summary: Occasionally useful.

Reviewed By: @int3, @elgenie

Differential Revision: D1695998

Signature: t1:1695998:1416530544:befee9d06783c4130d824db3191905f7a20587f7
Cleanup of hfsort

Summary: I want to embed the core of hfsort into hhvm to use for perf based
jit relocation, so move it into its own namespace, and move error() and TRACE
out of the core so they can be replaced with something more appropriate when
running from hhvm.

Reviewed By: @ottoni

Differential Revision: D1697874

Signature: t1:1697874:1416607428:0c68d05310bd047b6bf7d9db4be8dceeb5dbaaab