This made it awkward for user code to extract the query value for use in other applications; This would otherwise have to be xml decoded again.
Casting has been promoted to the templating level via DBField::create_field and a `SearchForm.casting` config setting.
The specific situation is if the SearchForm.ss is overriden, and the
$SearchQuery parameter is used in the template. This will throw a Notice
in case the form is rendered without searching.
