Added 20 sets to [DGC] Collection

Previews & DDL:

	[DGC] 2008.10 No.641 Azusa Nagasawa 長澤あずさ
	[DGC] 2008.10 No.642 Yui Kawakita 川北結衣
	[DGC] 2008.10 No.643 Ririna Hasegawa 長谷川りりな
	[DGC] 2008.11 No.644 Kana Tsugihara 次原かな
	[DGC] 2008.11 No.645 Shiori Yokoi 横井詩織
	[DGC] 2008.11 No.646 Yuka Mizusawa 水沢友香
	[DGC] 2008.11 No.647 Ayaka Noda 野田彩加
	[DGC] 2008.11 No.648 Minori Hatsune 初音みのり
	[DGC] 2008.11 No.649 Minori Hatsune 初音みのり
	[DGC] 2008.11 No.650 Kotone Amamiya 雨宮琴音
	[DGC] 2008.11 No.651 Hikari Asano 浅野光
	[DGC] 2008.11 No.652 Aya Misaki 美咲亜矢
	[DGC] 2008.11 No.653 Miku Narita 成田未来
	[DGC] 2008.11 No.654 Misaki Tachibana 立花美咲
	[DGC] 2008.11 No.655 Isa Aoki 青木衣沙
	[DGC] 2008.12 No.656 Natsuko Tatsumi 辰巳奈都子
	[DGC] 2008.12 No.657 Seiko Ando 安藤成子
	[DGC] 2008.12 No.658 Rika Kawamura 川村りか
	[DGC] 2008.12 No.659 Reika Osako 大迫麗香
	[DGC] 2008.12 No.660 Sana 紗奈