Methods to calculate amounts
fixed issue in inserting date values
Added transaction classes
Merge branch 'development' of https://github.com/omnipos/OmniPOSDesktop into development

Conflicts:
	OmniPOS/src/com/omnipos/models/OrderInfo.java
	OmniPOS/src/com/omnipos/models/OrderItem.java
	OmniPOS/src/com/omnipos/tools/DateUtils.java