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/classes/properties.py

@@ -0,0 +1,65 @@
+from __future__ import unicode_literals
+
+import six
+
+
+class NonDataProperty(object):
+	"""Much like the property builtin, but only implements __get__,
+	making it a non-data property, and can be subsequently reset.
+
+	See http://users.rcn.com/python/download/Descriptor.htm for more
+	information.
+
+	>>> class X(object):
+	...   @NonDataProperty
+	...   def foo(self):
+	...     return 3
+	>>> x = X()
+	>>> x.foo
+	3
+	>>> x.foo = 4
+	>>> x.foo
+	4
+	"""
+
+	def __init__(self, fget):
+		assert fget is not None, "fget cannot be none"
+		assert six.callable(fget), "fget must be callable"
+		self.fget = fget
+
+	def __get__(self, obj, objtype=None):
+		if obj is None:
+			return self
+		return self.fget(obj)
+
+
+# from http://stackoverflow.com/a/5191224
+class ClassPropertyDescriptor(object):
+
+	def __init__(self, fget, fset=None):
+		self.fget = fget
+		self.fset = fset
+
+	def __get__(self, obj, klass=None):
+		if klass is None:
+			klass = type(obj)
+		return self.fget.__get__(obj, klass)()
+
+	def __set__(self, obj, value):
+		if not self.fset:
+			raise AttributeError("can't set attribute")
+		type_ = type(obj)
+		return self.fset.__get__(obj, type_)(value)
+
+	def setter(self, func):
+		if not isinstance(func, (classmethod, staticmethod)):
+			func = classmethod(func)
+		self.fset = func
+		return self
+
+
+def classproperty(func):
+	if not isinstance(func, (classmethod, staticmethod)):
+		func = classmethod(func)
+
+	return ClassPropertyDescriptor(func)