(Tkinter.py): Add support for Frame(w, class_="classname") as an alternative

	to Frame(w, cnf={"class": "classname"}).  I think this is the only
	widget other than Toplevel that needs to be concerned about setting
	the widget's class (-class must be the first option on the Tcl
	widget creation command).

Lib/lib-tk/Tkinter.py

@@ -1219,7 +1219,10 @@ class Frame(Widget):
 	def __init__(self, master=None, cnf={}, **kw):
 		cnf = _cnfmerge((cnf, kw))
 		extra = ()
-		if cnf.has_key('class'):
+		if cnf.has_key('class_'):
+			extra = ('-class', cnf['class_'])
+			del cnf['class_']
+		elif cnf.has_key('class'):
 			extra = ('-class', cnf['class'])
 			del cnf['class']
 		Widget.__init__(self, master, 'frame', cnf, {}, extra)

Lib/tkinter/Tkinter.py

@@ -1219,7 +1219,10 @@ class Frame(Widget):
 	def __init__(self, master=None, cnf={}, **kw):
 		cnf = _cnfmerge((cnf, kw))
 		extra = ()
-		if cnf.has_key('class'):
+		if cnf.has_key('class_'):
+			extra = ('-class', cnf['class_'])
+			del cnf['class_']
+		elif cnf.has_key('class'):
 			extra = ('-class', cnf['class'])
 			del cnf['class']
 		Widget.__init__(self, master, 'frame', cnf, {}, extra)