bpo-30722: Make redemo work with Python 3.6+ (GH-2311)

Misc/NEWS.d/next/Tools-Demos/2017-10-23-19-45-52.bpo-30722.ioRlAu.rst

+Make redemo work with Python 3.6 and newer versions.
+
+In Python 3.6, flags like re.DOTALL became members of an enum.IntFlag so
+usages like ``getattr(re, 'DOTALL')`` are invalid.
+
+Also, remove the ``LOCALE`` option since it doesn't work with string
+patterns in Python 3.
+
+Patch by Christoph Sarnowski.

Tools/demo/redemo.py

@@ -75,7 +75,6 @@ class ReDemo:
         self.boxes = []
         self.vars = []
         for name in ('IGNORECASE',
-                     'LOCALE',
                      'MULTILINE',
                      'DOTALL',
                      'VERBOSE'):
@@ -83,7 +82,7 @@ class ReDemo:
                 frame = Frame(self.master)
                 frame.pack(fill=X)
                 self.frames.append(frame)
-            val = getattr(re, name)
+            val = getattr(re, name).value
             var = IntVar()
             box = Checkbutton(frame,
                     variable=var, text=name,