Make h_indirect more efficient

[jbangert]

As far as I see it, the current mechanism for h_indirect introduces one unneeded function call. Why not copy the contents of HParser in h_bind_indirect (and therefore the vtable)? This removes the need for the proxy design pattern currently in use. Maybe isValidRegular breaks, but otherwise we could reduce overhead/complexity quite a bit by removing the indirection at parse time

[abiggerhammer]

Try it out, run a benchmark, and send a PR? I'm happy to include speed improvements, but those are farther down the road for us -- right now we're focused on platform compat and debugging.