book/line: felder für quantity, etc.

__init__.py

@@ -4,7 +4,13 @@
 # full copyright notices and license terms.
 
 from trytond.pool import Pool
+from .types import Type
+from .book import Book
+from .line import Line
 
 def register():
     Pool.register(
+        Type,
+        Book,
+        Line,
         module='cashbook_investment', type_='model')