Remove main.h in DDS plugin.

Change-Id: I86b805d60755c463c321146e923469a9d7b006e4
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Fix build of the DDS plugin without QDataStream

Change-Id: I854c3bd82f244a6c45d91b08c3f1271538fd536a
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>