I Use a much faster and easier way to create a local copy of the codex without installing a local server and without installing copy of mediawiki, its called ScrapBook which is a Firefox extension, that helps you to save Web pages and manage the collection. Key features are lightness, speed, accuracy and multi-language support.
using it’s Save Web site (In-depth Capture)feature you can set the directories you want to save , which in your case would be Function Reference and Template Tags
you can also organize your collections just like bookmarks, edit saved files and highlight key parts of pages and the best thing about it is the built in full text search.