Bug 11773: setup wizard UI flow improvements

Add a new "Reconfigure" prompt that is displayed after
  bootstrapping fails. This makes it so users experience the
  same configuration sequence each time rather than forcing
  them to move backwards through the wizard pages.
Add a new "Remove Settings and Connect" prompt that is
  displayed if the user clicks "Connect" while some bridge or
  proxy settings are present. This avoids a problem where old
  settings may be used without users being aware of them.
Improve some of the configuration prompts and status text based
  on early feedback from UC Berkeley usability studies.