修正陈圣超 salesheetPO和salesheet
Merge branch 'master' of
ssh://git@github.com/minusone13/InvoicingSystem.git

Conflicts:
	GiftBillPO.txt
	LevelStrategyPO.txt
	ReachStrategyPO.txt
	SaleSheetPO.txt
	User.ser
Merge branch 'master' of
ssh://git@github.com/minusone13/InvoicingSystem.git
实现商品管理界面的增删改查功能