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- need to be able to call the response function even if it wasn't called by
  the Fcommand, since Fcommands that don't care about bg code can avoid
  calling the response function and everything still works all right
  (because the extension is waiting for the response func to be called).
Add Util.addInternalOptions

- to be used in factotum.js when creating the Fcommand code string
Support common options for all Fcommands

- --help to popup help for the Fcommand
- --debug to drop into debugger when executing the Fcommand's code
- --debug=bg to drop into debugger when executing the Fcommand's bg
  code