print -> info; end the horror of print vs. print()

Although we could use print() from __future__, this messes
up scripts which use examples as modules.

The simple, if not nicest for 2.7, solution is to use
info(), output() and other mininet.log functions. The disadvantage
is that we may have to adjust things if we change info() to
add automatic newlines, but we can burn that bridge in Mininet
3.x.

examples/baresshd.py

@@ -6,31 +6,32 @@ import sys
 
 from mininet.node import Host
 from mininet.util import ensureRoot, waitListening
+from mininet.log import info, warn, output
 
 
 ensureRoot()
 timeout = 5
 
-print( "*** Creating nodes" )
+info( "*** Creating nodes\n" )
 h1 = Host( 'h1' )
 
 root = Host( 'root', inNamespace=False )
 
-print( "*** Creating links" )
+info( "*** Creating link\n" )
 h1.linkTo( root )
 
-print( h1 )
+info( h1 )
 
-print( "*** Configuring nodes" )
+info( "*** Configuring nodes\n" )
 h1.setIP( '10.0.0.1', 8 )
 root.setIP( '10.0.0.2', 8 )
 
-print( "*** Creating banner file" )
+info( "*** Creating banner file\n" )
 f = open( '/tmp/%s.banner' % h1.name, 'w' )
 f.write( 'Welcome to %s at %s\n' % ( h1.name, h1.IP() ) )
 f.close()
 
-print( "*** Running sshd" )
+info( "*** Running sshd\n" )
 cmd = '/usr/sbin/sshd -o UseDNS=no -u0 -o "Banner /tmp/%s.banner"' % h1.name
 # add arguments from the command line
 if len( sys.argv ) > 1:
@@ -39,7 +40,7 @@ h1.cmd( cmd )
 listening = waitListening( server=h1, port=22, timeout=timeout )
 
 if listening:
-    print( "*** You may now ssh into", h1.name, "at", h1.IP() )
+    output( "*** You may now ssh into", h1.name, "at", h1.IP(), '\n' )
 else:
-    print( "*** Warning: after %s seconds, %s is not listening on port 22"
-            % ( timeout, h1.name ) )
+    warn( "*** Warning: after %s seconds, %s is not listening on port 22"
+            % ( timeout, h1.name ), '\n' )