fix static initialization fiasco (#116)
fix static initialization fiasco (#116)

and use type_index instead of hash_code for associative containers.

tested locally with latest envoy master.

Signed-off-by: Lizan Zhou <739047aeb4f72dac9d1867914b065926e8c1008d@tetrate.io>
envoyproxy/protoc-gen-validate,envoyproxy/protoc-gen-validate,envoyproxy/protoc-gen-validate,envoyproxy/protoc-gen-validate,envoyproxy/protoc-gen-validate