standardize lonelypages.py

- LonelyPagesBot extends pywikibot.Bot and uses self.userPut()
  with built-in 'always' option

- simplified check for orphan pages

- used the standard NewpagesPageGenerator()

- fix bug 69089

Change-Id: I18f64b215c6b45c9c27813cc116d476acfb51431
Merge "standardize lonelypages.py"