Merge pull request #26 from kveldscholten/master

update link modul
change cols to 2 on layouts
DatabaseMysql: Enabling update/insert of empty values.
User/GroupAccess: Changed to module/page/article in rows, groups in columns. (Redmine 116)
Merge branch 'master' of https://github.com/IlchCMS/Ilch-2.0
adding layout administration
Merge branch 'master' of https://github.com/IlchCMS/Ilch-2.0
User/GroupMapper: SQL statement fix, adding prefix. (Redmine 116)
Merge branch 'master' of https://github.com/IlchCMS/Ilch-2.0
adding links to hnavs