Add revid to Notification object
Add revid to Notification object

Since most edit-related notifications include revid attributes,
we should include the revids in the Notification objects as we're
building them (if they exist).

Change-Id: Ifdb98e7c79729a1c2f7a5c4c4366e28071a48239

wikimedia/pywikibot-core,happy5214/pywikibot-core,magul/pywikibot-core,Darkdadaah/pywikibot-core,npdoty/pywikibot,PersianWikipedia/pywikibot-core,hasteur/g13bot_tools_new,Darkdadaah/pywikibot-core,npdoty/pywikibot,happy5214/pywikibot-core,hasteur/g13bot_tools_new,wikimedia/pywikibot-core,jayvdb/pywikibot-core,hasteur/g13bot_tools_new,magul/pywikibot-core,jayvdb/pywikibot-core