Merge pull request #39 from marcSchneiter/master

fixed tests and added some new ones
Upadet so that the number of unbought items is displayed at the right border and you can input 0 in the quantity
Merge pull request #40 from cryptedp/master

Upadet so that the number of unbought items is displayed at the right bo...
Fixed item delete
Merge pull request #41 from broggi/master

Fixed item delete
Implemented Edit Item

And did some small additions to ItemHandler...
Merge pull request #42 from broggi/master

Implemented Edit Item
added test-project