M Debugger.py : Added clear_file_breaks()
M EditorWindow.py : Clear breaks when closed, commments->docstrings,
comment out some debugging print statements
M PyShell.py : comments->docstrings ; clarify extending EditorWindow
methods.
M RemoteDebugger.py: Add clear_all_file_breaks() functionality,
clarify some comments.
Use a repr() on the subprocess side when fetching dict values for stack.
The various dict entities are not needed by the debugger GUI, only
their representation.