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.

#!/usr/bin/env python

# Roundup requires Python 2.7+ as mentioned in doc\installation.txt
from __future__ import print_function
import sys

VERSION_NEEDED = (2, 7)

if sys.version_info < VERSION_NEEDED:
    print("Content-Type: text/plain\n")
    print("Roundup requires Python %s.%s or newer." % VERSION_NEEDED)
    sys.exit(0)