Prepare for 0.9.0 release

Signed-off-by: Thomas Graf <thomas@cilium.io>

Documentation: Adjust getting started guide to TPR policy

Signed-off-by: Thomas Graf <thomas@cilium.io>

Vagrant: Simplified Vagrantfile to get started

This new Vagrantfile is based on bento/ubuntu and uses the stock
Linux kernel as provided by Ubuntu. It install a Docker runtime
and then runs the Cilium agent and Cilium Docker plugin using the
released container images. The client binary is installed natively
for easy use.

Signed-off-by: Thomas Graf <thomas@cilium.io>

0.8.1 release

Signed-off-by: Thomas Graf <thomas@cilium.io>

release: 0.8.0 release

\o/

Signed-off-by: Thomas Graf <thomas@cilium.io>