Update protobuf submodule to fix Objective-C

bump version of C# to 0.7.1

Fixing sanity.

Update to nan 2.0

Do not use string_ref for output params.

Fix Python dockerfile.

Update Python release number to 0.11.0b1.

PHP: add examples for Apache and Nginx

It is very much unsafe to do so as the string_ref could point on a stack
variable of the callee.

Update Node module to 0.11.1 in anticipation of point release

Test coverage for callbacks added to Face futures

Further maintenance of Python dependencies

Fix erroneous attribute name in grpc.beta.secure_channel.

This defect was introduced in 9e4d0610. I had thought that
this code was exercised in tests but it is bypassed by the use of
grpc_test.beta.test_utilities.not_really_secure_channel. :-(

Fixing issue #3390

Shutting down warning about operations on closed sockets.

Backport the lock race fix to 0.11.

A transport op indicating a cancellation can be sent to the auth client
filter. In this case, the code should not assert that a context is not
null on this op.

Fix import that relied on Cocoapods' unique behavior

Update namespace of C# routeguide example

Plain log message should not be treated as format string

Fixes #3203

We entered a live lock race between the promotion callback and pollers,
which was only resolved when the background executor got lucky enough to
pick up the async work.

Fixed a couple of memory leaks in Node library

Fixed a couple of incorrect "this" references in Node library

Don't do .Wait() in async context.

Failing to use await can result in deadlock. This is likely to be the cause of shutdown hangs in #3347.