Url should be given as relative path (to webroot)
Correct link construction from js

Conflicts:
	lib/app.php
	lib/base.php
	lib/minimizer/css.php
	lib/minimizer/js.php
	lib/template.php
	lib/util.php

Made OC_Filestorage_Local and OC_Filestorage_Shared extend OC_Filestorage_Common
Set searchInDir() to protected instead of private in OC_Filestorage_Local and OC_Filestorage_Shared
Added class documentation to OC_Filestorage_Common
Cleaned up OCA_Versions::expireAll()