Updated the suite of handler classes with documentation.

Updated XMLStream to return True or False from removeHandler to indicate if the handler
existed and was removed.

Waiter handlers now unregister themselves after timing out.

sleekxmpp/xmlstream/xmlstream.py

@@ -357,8 +357,10 @@ class XMLStream(object):
 					return False
 
 	def registerHandler(self, handler, before=None, after=None):
-		"Add handler with matcher class and parameters."
-		self.__handlers.append(handler)
+ 		"Add handler with matcher class and parameters."
+ 		if handler.stream is None:
+ 			self.__handlers.append(handler)
+ 			handler.stream = self
 
 	def removeHandler(self, name):
 		"Removes the handler."
@@ -366,8 +368,10 @@ class XMLStream(object):
 		for handler in self.__handlers:
 			if handler.name == name:
 				self.__handlers.pop(idx)
-				return
+				return True
 			idx += 1
+		return False
+
 
 	def registerStanza(self, stanza_class):
 		"Adds stanza.  If root stanzas build stanzas sent in events while non-root stanzas build substanza objects."