Make sure the originally referenced controller class init() method is called
Fix issue 34

Apply sminnee's suggested fix
(https://github.com/silverstripe/silverstripe-subsites/issues/34) to
ensure the entire where section of the query is checked for ID
Fix issue 18

Allow addition of analytics code to subsite via cms
(https://github.com/silverstripe/silverstripe-subsites/issues/18)