Use consistent Exception for user selecting quit

Add a QuitKeyboardInterrupt as subclass of KeyboardInterrupt

Add new methods to pywikibot.Bot to:
- quit(): raises QuitKeyboardInterrupt
- run(): if self.generator is defined, call treat() for each page

Split pywikbot.Bot.userPut to create method userConfirm(),
which calls self.quit() if user enters 'q'.

Display edit summary to be used in userPut().

Alter scripts which allowed input of 'q' to quit, subclassing them
to pywikibot.Bot, and using self.userPut() or self.quit() to
cascade the break out of processing pages.

Fixes bug: 68663 misspelling doesnt quit on user input 'q'

Change-Id: I84cdc5dcb8626d2cc1d18f963a8d6fdf4c99da6a