standardize delete.py

- DeletionRobot extends pywikibot.Bot with an options dict
  and built-in 'always' option

- Bug 63800: call handleArgs before GeneratorFactory
  per I134529f3a914225d3473b95ca771cf7e7be01a36

Change-Id: I7ded2d3e2ab2ce3452f1a99819c1843dbfb33a8e