Move all .py that are supposed to be run as __main__ under ./scripts so there is no need to manipulate sys.path to import modules. Runby cleanup
for #201
- configured sccache on buildkite windows machines - final result is sent to phabricator from "summary.py" that waits for both builds to complete - extracted "add_url_artifact" to a runnable script - reorganized code and fixed some of TODOs