Commission Regulation (EC) No 249/2006 of 13 February 2006 amending Regulations (EC) No 2430/1999, (EC) No 937/2001, (EC) No 1852/2003 and (EC) No 1463/2004 as regards the terms of the authorisation of certain additives in feedingstuffs belonging to the group of coccidiostats and other medicinal substances