test dir classes and tests, errors with Client and clientTableModel ...
Merge branch 'master' of https://github.com/Slicey4/homework_3

Conflicts:
	src/ee/ut/math/tvt/salessystem/domain/data/Client.java
	src/ee/ut/math/tvt/salessystem/domain/data/SoldItem.java
	src/ee/ut/math/tvt/salessystem/ui/model/SalesSystemModel.java
	src/ee/ut/math/tvt/salessystem/ui/tabs/PurchaseTab.java