Comments on taleinat.20140219.IDLE_ClearWindow_extension.patch.

In 3.6, module names are lowercase, not too long.  Also, I am trying to consolidate small files, not multiply them.

I am trying to convert existing built-in extensions to built-in features, not add new extension files. 

The options menu seems like a strange place for the menu item.  Since this patch is for Shell, I would put it on the Shell menu.  Select All == Control A (Edit menu) + Backspace or Delete clears editor and output windows. (I could add this to the doc.)  The issue with Shell, as Roger noted in his original post, is the current mechanism to prevent deletion.

This suggests an alternate solution: only protect the current prompt (which I would like to move to a sidebar anyway).  There could be an option to making Shell history editable or not?  Why should people have to save-load or copy-paste to edit a shell session?  (Currently, the Rt click context menu displays an apparently active 'Cut' that does not work.)  The main issue is that people might edit past input, hit return, and expect the code to run.  This could be made to work.  

What to delete?  Everything prior to last prompt is plausible when IDLE is paused waiting for code input.  It is wrong if one is trying to stop output since the last prompt.  These are two different use cases (Raymond mentioned both in duplicate #27771).

1. Cosmetic cleanup of a long session.  A Shell => Clear (everything) and Restart (and emit a new prompt) would work for this.

2. Recovery from excessively many or long lines.  (see #27750, for instance).  For this, one may only want to delete the most recent program output (and ignore anything that keeps coming before the next prompt is printed).  The need here is for Shell to remain more responsive than it currently does.

Undo-able?  Cntl-A + delete is already undo-able.  Clear and Restart would be, as Restart clears the undo stack.  I think emergency deletion should not be.