Replaced nodelist and nodemap in CLI with mn

Updated Mininet to be more compliant with dict
Fixes #182

mininet/net.py

@@ -236,8 +236,24 @@ class Mininet( object ):
 
     def __iter__( self ):
         "return iterator over nodes"
+        #or dow we want to iterate of the keys i.e. node.name like a dict
         return chain( self.hosts, self.switches, self.controllers )
 
+    def __len__( self ):
+        return len( self.hosts ) + len( self.switches ) + len( self.controllers )
+
+    def __contains__( self, item ):
+        return item in self.keys()
+
+    def keys( self ):
+        return [ node.name for node in self.__iter__() ]
+
+    def values( self ):
+        return list( self.__iter__() )
+
+    def items( self ):
+        return zip( self.keys(), self.values() )
+
     def addLink( self, node1, node2, port1=None, port2=None,
                  cls=None, **params ):
         """"Add a link from node1 to node2