standardize nowcommons.py
standardize nowcommons.py

- NowCommonsDeleteBot extends pywikibot.Bot

- pass options to the bot class constructor
  instead of using global variables

- BREAKING: the '-autonomous' argument has been replaced
  with the standard '-always'; the former is provisionally
  retained for backwards compatibility

- replaced NowCommonsDeleteBot.urlname() with Page.title(asUrl=True)

- the argument parsing has been optimized

- replaced ImagePage.fileIsOnCommons() with ImagePage.fileIsShared()

- pywikibot.inputChoice() always returns the short variant, lowercase

Change-Id: I1cc6b5734237d143c8100f3c26c20d78c36924c6

hasteur/g13bot_tools_new,happy5214/pywikibot-core,wikimedia/pywikibot-core,happy5214/pywikibot-core,jayvdb/pywikibot-core,jayvdb/pywikibot-core,h4ck3rm1k3/pywikibot-core,h4ck3rm1k3/pywikibot-core,valhallasw/pywikibot-core,trishnaguha/pywikibot-core,VcamX/pywikibot-core,wikimedia/pywikibot-core,TridevGuha/pywikibot-core,hasteur/g13bot_tools_new,npdoty/pywikibot,emijrp/pywikibot-core,darthbhyrava/pywikibot-local,magul/pywikibot-core,magul/pywikibot-core,hasteur/g13bot_tools_new,xZise/pywikibot-core,smalyshev/pywikibot-core,icyflame/batman,Darkdadaah/pywikibot-core,Darkdadaah/pywikibot-core,npdoty/pywikibot,PersianWikipedia/pywikibot-core