Hybrid network fixes

This is going to have several fixes to help ease us into our hybrid network.

- '-p <port_number>' is being ignored right now. First commit fixes it.
Can you describe the problem? The code is expected to throw a `RuntimeError` is you are trying to decrypt without a `privkey` or if `pyelliptic` detects a bad MAC. It is expected to throw an `Exception` in all other abnormal cases. The *caller* should catch these exceptions and deal with them.