A slight modification of the python.org debug architecture

Currently, the pdb module executes operates the break point call back and executes five or six display variable commands.  Leave that module as it is,except the five ore six user commands are executed from a module called dgui.  or dgui import pdb.  But dgui case be any window that meets the text display and grb functions.  The current python shell simply becomes a simple instance of dgui in which the display and grab methods are implemented in a shell, but it is a valid dgui otherwise.

The thing is, debug explicitly involves display and grab. So make the dgui window mandatory, you have to at  least have the shell gui.  Any of the dgui interfaces can use calls to exec() to obtain any variable contents, which the shell does implicitly.

The source code editor can still be stand alone, or it can implement the dgui.