No longer need to edit the terminator source! :D

Up to you if you take this or not.  I was a bit liberal with the number of edits I made.  Improvements include the following:

* No longer need to edit the terminator source.  Uses inspect to grab the parent Terminal class object.
* One option 'command' with a few template variables replaced.  This means this can now work with any editor (or app).
* Removed the open_file() function which is no longer needed.