(Bug 59700) Generate list of SMW settings via Special:SMWAdmin

It can be daunting to find all relevant SMW configurations in one place
therefore the following change will allow to generate a simple list via
Special:SMWAdmin.

Display is only permitted to people who have Special:SMWAdmin rights.
Merge pull request #82 from SemanticMediaWiki/admin

(Bug 59700) Generate list of SMW settings via Special:SMWAdmin