Don't define enablePW by default
smarter match for IP address in nodes

- add 'connnected?' method to ssh/telnet to query if or not we're
  connected
- subclass OxidizedError from StandardError, all future OxidizedErrors
  should be subclasssed from this.
Subclass all errors from OxidizedError
IOS prompt now matches in config mode
bumpup gemspec