Add 'fundraising' role

This patch adds a 'fundraising' role which configures the following things:

 * Switches MediaWiki to 'fundraising/1.22' branch
 * rsyslog w/fundraising configs
 * ContributionTracking, ParserFunctions, FundraisingEmailUnsubscribe &
   DonationInterface MediaWiki extensions

Change-Id: Ifebd54d4307e0ca3997d8572dc93f31a2622fa64