Move init() into Mininet() and remove calls (since called automatically.)

Note: we should probably rename it "setup()" to avoid confusion.

bin/mn

@@ -19,7 +19,7 @@ import time
 from mininet.clean import cleanup
 from mininet.cli import CLI
 from mininet.log import lg, LEVELS, info, warn
-from mininet.net import Mininet, init
+from mininet.net import Mininet
 from mininet.node import Host, CPULimitedHost, Controller, OVSController, NOX
 from mininet.node import RemoteController, UserSwitch, OVSKernelSwitch
 from mininet.link import Intf, TCIntf
@@ -27,6 +27,7 @@ from mininet.topo import SingleSwitchTopo, LinearTopo, SingleSwitchReversedTopo
 from mininet.topolib import TreeTopo
 from mininet.util import makeNumeric, custom
 
+
 def customNode( constructors, argStr ):
     "Return custom Node constructor based on argStr"
     cname, newargs, kwargs = splitArgs( argStr )
@@ -47,7 +48,6 @@ def customNode( constructors, argStr ):
     return custom
 
 
-
 # built in topologies, created only when run
 TOPODEF = 'minimal'
 TOPOS = { 'minimal': lambda: SingleSwitchTopo( k=2 ),
@@ -229,9 +229,6 @@ class MininetRunner( object ):
                     % self.options.verbosity )
         lg.setLogLevel( self.options.verbosity )
 
-        # validate environment setup
-        init()
-
     def begin( self ):
         "Create and run mininet."