use rcmd instead of quietRun when shutting down remote nodes
use ControlPersist ssh option to create a ControlMaster connection that will not die when a node dies
Some clarifications
raise exception when no prefixLen is set
Revert to old "Adding controller" message
Correctly call cli() rather than CLI()
Add setup() and dpctl() methods for LinuxBridge

Also adds docstrings.
Fixes #422
adding deleteIntfs option to switches and corresponding CLI command
explicit param call in cli command
use isinstance( obj, basestring) to allow unicode strings

fixes #448
type( foo ) is bar -> isinstance( foo, bar )
Fix typo. ;-p
Fix undefined sleep()
Remove unused imports
Make pylint happier for no particular reason
Merge pull request #449 from cdburkard/devel/cluster_controlPaths

use ControlPersist ssh option to fix ControlPath shutdown
Merge pull request #450 from mininet/sw-cmd

adding deleteIntfs option to switches and corresponding CLI command
DemoCLI -> ClusterCLI
Renamed to intfoptions.py for consistency
Rename examples.{intfOptions,multiLink} -> {intfoptions,multilink}