Added 20 sets to [DGC] Collection

Previews & DDL:

	[DGC] 2012.05 No.1021 Tsukushi つくし
	[DGC] 2012.05 No.1022 Shuri Watanabe 渡辺朱莉
	[DGC] 2012.06 No.1023 Kaho Takashima 高嶋香帆
	[DGC] 2012.06 No.1024 Mio Takaba 鹰羽澪
	[DGC] 2012.06 No.1025 Megumi Suzumoto 凉本めぐみ
	[DGC] 2012.06 No.1026 Yui Akane 朱音ゆい
	[DGC] 2012.06 No.1027 Miyuki Yokoyama 横山美雪
	[DGC] 2012.06 No.1028 JULIA
	[DGC] 2012.07 No.1029 Dan Mitsu 壇蜜
	[DGC] 2012.07 No.1030 Chika Tono 遠野千夏
	[DGC] 2012.07 No.1031 Kaho Kasumi かすみ果穂
	[DGC] 2012.07 No.1032 Chisato Shoda 翔田千里
	[DGC] 2012.07 No.1033 NINA
	[DGC] 2012.07 No.1034 Yukari Oda 小田ゆかり
	[DGC] 2012.08 No.1035 Misato Kashiuagi 柏木美里
	[DGC] 2012.08 No.1036 Ayumi Takahashi 高橋亜由美
	[DGC] 2012.08 No.1037 Aino Kishi 希志あいの
	[DGC] 2012.08 No.1038 Yumi Kazama 風間ゆみ
	[DGC] 2012.08 No.1039 Saki Ninomiya 二宮沙樹
	[DGC] 2012.08 No.1040 Shiori Asana 朝菜栞