change file name to static
pull new files
Merge branch 'master' of github.com:sorashiro/pos-java
Merge branch 'master' of github.com:sorashiro/pos-java
Merge branch 'master' of github.com:sorashiro/pos-java
Merge branch 'master' of github.com:sorashiro/pos-java
new Discount Class
add new DiscountItem Class
update DiscountItem Class
add get promotion function
fix codes