Merge github.com:grpc/grpc into footprints-on-the-sands-of-time

.gitignore

.travis.yml

BUILD

Makefile

build.json

include/grpc++/auth_context.h

include/grpc++/client_context.h

include/grpc++/server_context.h

include/grpc/grpc_security.h

src/core/iomgr/iomgr.c

src/core/iomgr/socket_windows.c

src/core/security/client_auth_filter.c

src/core/security/credentials.c

src/core/security/credentials.h

src/core/security/google_default_credentials.c

src/core/security/json_token.c

src/core/security/json_token.h

src/core/security/security_context.c

src/core/security/security_context.h

src/core/surface/server.c