dev 13.08.2014

changed \DisplayGallery::getPictureInformationArray() to static an moved
to GcHelpers::getPictureInformationArray() ,

changed \DisplayGallery::getAlbumInformationArray() to static an moved
to GcHelpers::getAlbumInformationArray() ,

created new Mehod: GcHelpers::getSubalbumsInformationArray