The things i had to change to get my own ship classes to work:
In the ShipClassDefs.xml for the constructors the tag <StaticBlueprintDef> is now replace by a <BlueprintDef> tag.
The ShipBlueprintDefs.xml has added a <ShipGroup> tag.
Constructor blueprints have moved from StaticShipBlueprintDefs.xml to ShipBlueprintDefs.xml
Hopes this helps.