Add new parameter $patrolFooterShown to hook ArticleViewFooter

Some extensions like PageTriage will be able to use this new
parameter to determine whether to show its own curation toolbar.

Change-Id: I07e85aa37edc994c5a2bf9d011976b91ff01ab14
Merge "Add new parameter $patrolFooterShown to hook ArticleViewFooter" into wmf/1.22wmf5