Alternative Calculation of Homepage Doctype

To calculate the doctype of the documents hosted by a doctype homepage, the service solely relies on the naming convention of an I18N key. Users who do not provide their doctypes in form of doctype add-ons cannot use this feature currently.

We therefore need an additional check to determine the doctype by looking at the Flags property of the doctype homepage. 

projectdoc.doctype-home, projectdoc.all, projectdoc.related.doctype.<doctype>

If the values above are present for the Flags property, the doctype is derived from the third property above (the property values may be specified in any order).