Joined Cases C-278/07 to C-280/07: Judgment of the Court (Second Chamber) of 29 January 2009 (references for a preliminary ruling from the Bundesfinanzhof — Germany) — Hauptzollamt Hamburg-Jonas v Josef Vosding Schlacht-, Kühl- und Zerlegebetrieb GmbH & Co. (Regulation (EC, Euratom) No 2988/95 — Protection of the European Communities' financial interests — Article 3 — Recovery of an export refund — Determining the limitation period — Irregularities committed before the entry into force of Regulation (EC, Euratom) No 2988/95 — Rule on limitation forming part of the general civil law of a Member State)