Update Metrolook.php

Bump version Bump compatibility to MediaWiki 1.25. If you want compatibility with Mediawiki 1.24, 1.23, 1.22, 1.21 please README.
Update README.md

Updating page you should add it mediawiki:common.css is for everything it will also affect other skin so keep it in its own metrolook.css page. to not affect other skins.
Update README.md
Update Metrolook

* Fix Upload image.
* Fixed some bugs.
* Added theme.css to add your custom css.
* Pages that are empty now show in red on the link.

Change-Id: Ib74b12357ccc3dae6fbf67741f0d72cb873c36d3
Update theme.css

Remove the customisation I had for my site. for the user to choose.
Update Metrolook.php

Bumping version to 2.4.2
Merge pull request #67 from paladox2015/master

Update