* invoke(), distinguish between command triggering source. Also add
support of auto transaction using App::AutoTransaction. Now all
command will support undo/redo by default.
* setupCheckable(), a helper function to Improve support of
PythonGroupCommand
* getObjectCmd(), helper function to output Python command to refer to
an object without ambiguity. Because with introduction of external
linking, an object can no longer be safely referred through the
current active document.
* Support auto MacroManager command logger. For commands that does not
log any output to MacroManager, a log entry of 'Gui.runCommand()' will
be auto generated.
* Support linked object in copyVisual()
* Modified do/runCommand() to print calling file and line number.
* Add various helper macros for run command involving a document or
object.
