Lot of standard performance tweaks for those who want them

After some cleanup in <https://www.mediawiki.org/wiki/Manual:Performance_tuning>
I decided to make a "live" version of the documentation, in puppet. Here it is.

Not tested; needs review by sysadmin/puppet/MediaWiki-Vagrant folks.
Maybe the 30 days caching should be moved to the "aggressive" option.

Change-Id: Ie73c7549557c63f19287c53c8a4fc7b07dbc8e93