Add simpler methods for instantiating TwoPartyServer/Client
Add simpler methods for instantiating TwoPartyServer/Client

rcrowder/pycapnp,SymbiFlow/pycapnp,jparyani/pycapnp,rcrowder/pycapnp,rcrowder/pycapnp,SymbiFlow/pycapnp,jparyani/pycapnp,tempbottle/pycapnp,SymbiFlow/pycapnp,tempbottle/pycapnp,jparyani/pycapnp,tempbottle/pycapnp,tempbottle/pycapnp,jparyani/pycapnp,rcrowder/pycapnp,SymbiFlow/pycapnp