Fix missing or shebangs and executable bits for scripts (#10318)

Tools/scripts/analyze_dxp.py

+#!/usr/bin/env python
 """
 Some helper functions to analyze the output of sys.getdxp() (which is
 only available if Python was built with -DDYNAMIC_EXECUTION_PROFILE).

Tools/scripts/diff.py

+#!/usr/bin/env python
 """ Command line interface to difflib.py providing diffs in four formats:
 
 * ndiff:    lists every line and highlights interline changes.

Tools/scripts/mailerdaemon.py

+#!/usr/bin/env python
 """mailerdaemon - classes to parse mailer-daemon messages"""
 
 import rfc822

Tools/scripts/patchcheck.py

+#!/usr/bin/env python
 import re
 import sys
 import shutil

Tools/scripts/redemo.py

+#!/usr/bin/env python
 """Basic regular expression demostration facility (Perl style syntax)."""
 
 from Tkinter import *