[!!!][+BUGFIX] Fix MVC Error Handling, and remove recursive Property Mapper configuration
We have seen that the property mapping configuration should
work non-recursively by default, to make sure the user does
not open security holes by accident.
As we do not have a use-case for recursive property mapping
configuration, this has been completely removed by now.
Furthermore, a workaround has been programmed which makes
the MVC error handling work with both Phoenix Plugins and
simple Packages like the Blog-Package.