fence: fixes and cleanups to fencing.py library
fence: fixes and cleanups to fencing.py library

- Do not report failure if a node is successfully powered off,
  but fails to power on.

- Change 'pass' to 'continue' so that comments and blank lines
  from stdin are ignored.

- Use the full path to ssh and telnet when executing the binaries.

stevenraspudic/resource-agents,asp24/resource-agents,asp24/resource-agents,asp24/resource-agents,stevenraspudic/resource-agents,stevenraspudic/resource-agents