Typha v0.5.1 pre-release for testing

• Update libcalico-go pin for new policy Types field
• Rev libcalico-go to pick up permissive ingress/egress validation change.
• Implement read/write timeouts in the Typha client.
• Fix typha command line client.
• Fix a couple of uncaught errors.
• bump libcalico-go to v1.7.1