The next hidden parameter in the form, which determines the redirect
following an update is set to the 'next' query parameter in the form.
If the query parameter does not exist, the HTTP_REFERER is used.
If neither exist, the user gets redirected to the dashboard.

Add the add item functionality. Also enforce a default value for item-type on forms. While the API allows for items without an item-type, the form's handling of it was inconsistant. Until we have a use case for items without an item type, a default is enforced.

Refactor views into multiple files prior to developing edit item features. Also changed the edit/create item urls.