Remove "from __future__ import print"

This was well-intentioned, but it causes more trouble
than it's worth.

Fixes #652

bin/mn

@@ -11,7 +11,6 @@ Example to pull custom params (topo, switch, etc.) from a file:
   sudo mn --custom ~/mininet/custom/custom_example.py
 """
 
-from __future__ import print_function
 from optparse import OptionParser
 import os
 import sys

examples/baresshd.py

@@ -2,7 +2,6 @@
 
 "This example doesn't use OpenFlow, but attempts to run sshd in a namespace."
 
-from __future__ import print_function
 import sys
 
 from mininet.node import Host

examples/cluster.py

@@ -74,7 +74,6 @@ Things to do:
 - hifi support (e.g. delay compensation)
 """
 
-from __future__ import print_function
 
 from mininet.node import Node, Host, OVSSwitch, Controller
 from mininet.link import Link, Intf

examples/controllers2.py

@@ -11,7 +11,6 @@ Note that one could also create a custom switch class and pass it into
 the Mininet() constructor.
 """
 
-from __future__ import print_function
 
 from mininet.net import Mininet
 from mininet.node import Controller, OVSSwitch

examples/cpu.py

@@ -4,7 +4,6 @@
 cpu.py: test iperf bandwidth for varying cpu limits
 """
 
-from __future__ import print_function
 
 from mininet.net import Mininet
 from mininet.node import CPULimitedHost

examples/linearbandwidth.py

@@ -23,7 +23,6 @@ of switches, this example demonstrates:
 
 """
 
-from __future__ import print_function
 
 from mininet.net import Mininet
 from mininet.node import UserSwitch, OVSKernelSwitch, Controller

examples/linuxrouter.py

@@ -27,7 +27,6 @@ Additional routes may be added to the router or hosts by
 executing 'ip route' or 'route' commands on the router or hosts.
 """
 
-from __future__ import print_function
 
 from mininet.topo import Topo
 from mininet.net import Mininet

examples/miniedit.py

@@ -20,7 +20,6 @@ OpenFlow icon from https://www.opennetworking.org/
 
 MINIEDIT_VERSION = '2.2.0.1'
 
-from __future__ import print_function
 from optparse import OptionParser
 # from Tkinter import *
 from Tkinter import ( Frame, Label, LabelFrame, Entry, OptionMenu, Checkbutton,

examples/mobility.py

@@ -19,7 +19,6 @@ to-do:
 - think about clearing last hop - why doesn't that work?
 """
 
-from __future__ import print_function
 
 from mininet.net import Mininet
 from mininet.node import OVSSwitch

examples/multiping.py

@@ -8,7 +8,6 @@ multiple hosts and monitor their output interactively for a period=
 of time.
 """
 
-from __future__ import print_function
 
 from mininet.net import Mininet
 from mininet.node import Node

examples/multipoll.py

@@ -5,7 +5,6 @@ Simple example of sending output to multiple files and
 monitoring them
 """
 
-from __future__ import print_function
 
 from mininet.topo import SingleSwitchTopo
 from mininet.net import Mininet

examples/nat.py

@@ -4,7 +4,6 @@
 Example to create a Mininet topology and connect it to the internet via NAT
 """
 
-from __future__ import print_function
 
 from mininet.cli import CLI
 from mininet.log import lg

examples/numberedports.py

@@ -6,7 +6,6 @@ Validate that the port numbers match to the interface name,
 and that the ovs ports match the mininet ports.
 """
 
-from __future__ import print_function
 
 from mininet.net import Mininet
 from mininet.node import Controller

examples/popen.py

@@ -5,7 +5,6 @@ This example monitors a number of hosts using host.popen() and
 pmonitor()
 """
 
-from __future__ import print_function
 
 from mininet.net import Mininet
 from mininet.node import CPULimitedHost

examples/popenpoll.py

@@ -2,7 +2,6 @@
 
 "Monitor multiple hosts using popen()/pmonitor()"
 
-from __future__ import print_function
 
 from mininet.net import Mininet
 from mininet.topo import SingleSwitchTopo

examples/scratchnet.py

@@ -8,7 +8,6 @@ but it exposes the configuration details and allows customization.
 For most tasks, the higher-level API will be preferable.
 """
 
-from __future__ import print_function
 
 from mininet.net import Mininet
 from mininet.node import Node

examples/simpleperf.py

@@ -9,7 +9,6 @@ iperf will hang indefinitely if the TCP handshake fails
 to complete.
 """
 
-from __future__ import print_function
 
 from mininet.topo import Topo
 from mininet.net import Mininet

examples/sshd.py

@@ -16,7 +16,6 @@ demonstrates:
 - running server processes (sshd in this case) on hosts
 """
 
-from __future__ import print_function
 import sys
 
 from mininet.net import Mininet

examples/test/test_sshd.py

@@ -4,7 +4,6 @@
 Test for sshd.py
 """
 
-from __future__ import print_function
 import unittest
 import pexpect
 from mininet.clean import sh

examples/treeping64.py

@@ -2,7 +2,6 @@
 
 "Create a 64-node tree network, and test connectivity using ping."
 
-from __future__ import print_function
 
 from mininet.log import setLogLevel
 from mininet.node import UserSwitch, OVSKernelSwitch  # , KernelSwitch

mininet/cli.py

@@ -25,7 +25,6 @@ list all nodes ('nodes'), to print out the network topology
 and bandwidth ('iperf'.)
 """
 
-from __future__ import print_function
 from subprocess import call
 from cmd import Cmd
 from os import isatty

mininet/util.py

@@ -1,6 +1,5 @@
 "Utility functions for Mininet."
 
-from __future__ import print_function
 
 from mininet.log import output, info, error, warn, debug
 

util/versioncheck.py

@@ -1,6 +1,5 @@
 #!/usr/bin/python
 
-from __future__ import print_function
 from subprocess import check_output as co
 from sys import exit
 

util/vm/build.py

@@ -26,7 +26,6 @@ Basic idea:
 
 """
 
-from __future__ import print_function
 import os
 from os import stat, path
 from stat import ST_MODE, ST_SIZE