Update jaraco.windows to v3.6:

Dependencies:
* backports.functools-lru-cache	1.2.1
* jaraco.classes	1.3
* jaraco.collections	1.3.2
* jaraco.functools	1.11
* jaraco.structures	1.0
* jaraco.text	1.7
* jaraco.ui	1.4
* jaraco.windows	3.6
* more-itertools	2.2
* path.py	8.2.1
* six	1.10.0

libs/jaraco/ui/cmdline.py

@@ -0,0 +1,62 @@
+import argparse
+
+import six
+from jaraco.classes import meta
+from jaraco import text
+
+
+@six.add_metaclass(meta.LeafClassesMeta)
+class Command(object):
+	"""
+	A general-purpose base class for creating commands for a command-line
+	program using argparse. Each subclass of Command represents a separate
+	sub-command of a program.
+
+	For example, one might use Command subclasses to implement the Mercurial
+	command set::
+
+		class Commit(Command):
+			@staticmethod
+			def add_arguments(cls, parser):
+				parser.add_argument('-m', '--message')
+
+			@classmethod
+			def run(cls, args):
+				"Run the 'commit' command with args (parsed)"
+
+		class Merge(Command): pass
+		class Pull(Command): pass
+		...
+
+	Then one could create an entry point for Mercurial like so::
+
+		def hg_command():
+			Command.invoke()
+	"""
+
+	@classmethod
+	def add_subparsers(cls, parser):
+		subparsers = parser.add_subparsers()
+		[cmd_class.add_parser(subparsers) for cmd_class in cls._leaf_classes]
+
+	@classmethod
+	def add_parser(cls, subparsers):
+		cmd_string = text.words(cls.__name__).lowered().dash_separated()
+		parser = subparsers.add_parser(cmd_string)
+		parser.set_defaults(action=cls)
+		cls.add_arguments(parser)
+		return parser
+
+	@classmethod
+	def add_arguments(cls, parser):
+		pass
+
+	@classmethod
+	def invoke(cls):
+		"""
+		Invoke the command using ArgumentParser
+		"""
+		parser = argparse.ArgumentParser()
+		cls.add_subparsers(parser)
+		args = parser.parse_args()
+		args.action.run(args)