Add use_tls, use_test_ca, and server_host_override flags to Python
stress client. These are needed to run the stress client against a local
server that is using tls.

tcp_client_posix: Don't overwrite error descr.

Reduce noise in interop test output

Expose message limit constants so that users can reference them

Rewrote connectivity status logic for gRPC LB

Fix windows benchmarks and upload all 3 reports

Added more testing for grpclb tokens

Enable running C# benchmarks on Windows

Add default arguments to python interop client

Use JSON tree for service config channel arg.

Undo wrong NULLing in grpclb

Support percent-encoding status messages

Kicking off fullstack micro-benchmarking

Redact sensitive data from api traces

Fix usage of GPR_UNREACHABLE_CODE

Fix symbol conflicts in grpc_tool_test