feat: can use escaped tokens inside quotes including quotes. Change tokenizer to support: cmd with arg "string with embedded \" double quote" works for single quotes too. Mixed quotes can skip the \" or \' escaping. Also: quoted cmds args "can include \n newline, \t tab and \r return" Added a doc example, also tests for new feature.

from roundup.dist.command.build import build_message_files, check_manifest
from setuptools.command.install_lib import install_lib as base

class install_lib(base):

    def run(self):
        check_manifest()
        build_message_files(self)
        base.run(self)