(bug 56035) RecentChangesPageGenerators arguments do

Added to Pagegenerators additional args present in
site.recentchanges() and updated/aligned doc strings in
site.py and pagegenerators.py.

https://bugzilla.wikimedia.org/show_bug.cgi?id=56035

Change-Id: I0d3e160d3fa0a9a5266bdb5688fb60728a8ad716
Merge "(bug 56035) RecentChangesPageGenerators arguments do"