Have server hold a reference to completion queues

Fixes podspec and removes old generated files

ServiceAccountCredentials support for C#

Fix a race in QPS client shutdown

Few VS2010 fixes.

adding auth interop tests for C# to grpc_docker.sh

Ignore SIGPIPE

Fix errors and warnings breaking compilation under GCC+Windows (MSYS2/MinGW)

-) = delete isn't supported. Moving destructor out of scope.
-) variadic templates aren't supported. Replacing emplace_back's construction.
-) C++11's {} inline construction isn't supported. Adding temporary variables.
-) std::list<> can't work on a non-declared class. Changing to a raw pointer.

Pass deadline to call details for batch calls

In the presence of garbage collectors, this helps ensure that completion
queues outlive the servers that depend upon them.