Choosing port and interface.
Merge pull request #375 from bearstech/host_and_port

Choosing port and interface.
Fixed issue introduced in #335

Forgot to add the RPC method, so workers would always fail invoking add_worker.

This was a pure cosmetic change that didn't lead to any deeper issues
Merge pull request #376 from erikbern/erikbern/fix-335

Fixed issue introduced in #335
Don't crash if loading a corrupt pickle state file

Previously the luigi server would crash on startup if the pickle file that stores its state is corrupt for some reason