* Removes rogue direct usage of subprocess module by proper utils.execute calls * Adds a run_as_root parameter to utils.execute, that prefixes your command with FLAG.root_helper (which defaults to 'sudo') * Turns all sudo calls into run_as_root=True calls * Update fakes accordingly * Replaces usage of "sudo -E" and "addl_env" parameter into passing environment in the command (allows it to be compatible with alternative sudo_helpers) * Additionally, forces close_fds=True on all utils.execute calls, since it's a more secure default