Firebase: Merge changes with master.#77

Merged

sarvaniv merged 5 commits intocloudendpoints:firebasefrom

sarvaniv:firebase

Jan 24, 2017

Commits on Jan 11, 2017

Commits on Jan 12, 2017

Align with latest istio/proxy. (#73)
chowchow316
authored

Commits on Jan 14, 2017

Support HEAD request in transcoding (#74)
lizan
authored

Commits on Jan 23, 2017

Fixing bazel install for ubuntu salve
sebastienvas
committed