Merge Py Idle changes:

Merge Py Idle changes:

Rev 1.6 GvR
Finally fix SF bug #441172, using a variant of patch ##443626:
canceling an edit operation would not revert the value of the field.
The fix takes care to destroy the Entry object, as suggested in the
patch.

Rev 1.7 Geiger Ho / GvR
(previously applied - Idlefork Rev 1.3)

Rev 1.8 doerwalter
(string methods)