* Add isort_code.sh to sanity tests
* Run tools/distrib/isort_code.sh
* Fine tune the import order for relative imports
* Make pylint and project generation happy
* Fix a few corner cases
* Use --check instead of --diff
* The import order impacts test result somehow
* Make isort print diff and check output at the same time
* Let tools/run_tests/python_utils be firstparty library
* Run isort against latest HEAD
This grossly simplifies the protoc invocation to:
python -m grpc.protoc.compiler --python_out=... --grpc_python_out=...
[...] --plugin=protoc-gen-python-grpc=grpc_python_protoc_plugin... [...]
The source code is moved from src/python to
src/python/src. A setup.py is added at
src/python. The build_python.sh and
run_python.sh scripts are updated to build
and run the Python tests by building a
package and installing it in the developer's
Python 2.7 virtual environment.