Fix cmake build on Windows on internal_ci

Internal CI: Add macos grpc_master job

Use run_tests_matrix.py for running internal_ci master tests

Reports GC stats in qps workers

Reintroduce a lambda capture as part of C++11-izing code

Better presentation of reports in internal CI

New version of grpclb end2end test

Remove unused import in grpcio_health_checking.

Fix imports in generated gRPC Python code.

Fix printf format

Fix bogus asserts

Remove leftover thrift mentions

.proto and BUILD files can now in differnt dirs

Added verbose option to run_interop_test to ease tracing the commands…

Removed 3rd party dep on thrift

Add gflags to Mac build from source instructions

Note that gflags is already listed as something to install under Linux before build from source and running tests but was not included on Mac.

Fix potential memory leak, cleanup some code

Bazel build rule for //test/cpp/util:grpc_cli

Update performance VM init script

This changes the import style for proto dependencies from a) to b).
a) "import a.b.c as x"
b) "from a.b import c as x"

Using statement a) causes problems when using __init__ files. If module
"a.b" has an __init__.py file which is importing the python generated
grpc code "a.b.d", then we cannot import a module named "a.b.c" because
the module "a.b" does not exist yet. In this case python will throw:
AttributeError: 'module' object has no attribute 'b'

This PR adapts the code to use the same logic as in:
/google/protobuf/compiler/python/python_generator.cc

Optimize framing a little