Label printing: New layouts and more

Added one normal new layout and a new barcode layout for ITDB. We used
them with Avery Zweckform sheets and they work really good.

Below some screenshots of how the labels will look and what changes at
the interface. Please ignore the borders around the labels ... had not
the time to make it fit into the label, so I just used the existing
labels without any modification which are obviously not suitable with
adjustment.

Had some troubles with the github pullm request, so please ignore the listitems2.php since this is already included in my other pull request ;) So I reverted it to not include it in this pull request here.

Screenshots:
Print Labels Page:
![image](https://cloud.githubusercontent.com/assets/2871833/4646677/6f4d01ba-5475-11e4-9c17-f521b167f83b.png)

Original Layout - called it Layout 1:
![image](https://cloud.githubusercontent.com/assets/2871833/4646664/5a76539a-5475-11e4-9a04-6372b52c8711.png)

Our modified layout - called it Layout 2:
![image](https://cloud.githubusercontent.com/assets/2871833/4646692/932d003a-5475-11e4-9763-fe3425ec66c4.png)

A simple barcode / QR-Code only layout
Just set all the other stuff to nothing -> " ", so just the QR-Code is printed on the label. With the right settings it should be possible to print 2 qr-codes / barcodes on one label :)
![image](https://cloud.githubusercontent.com/assets/2871833/4646720/d5cff4d8-5475-11e4-807b-15d5b0aa7284.png)


If you like to add the data of the Avery Zweckform labels which work here:

ZWE3651:
ldata(10, 4, 51.3,28.7, 29.3, 52.0, 2.5, 1.0, 2.85, 1.0,"ZWE3651",255,0,6,9,19,7,1,1,1,"Header Text","","4","4","A4","your-domain.com/")

QR-Only Large
ldata(10, 8, 25.65,28.7, 29.3, 25.8, 1.0, 1.0, 2.5, 1.0,"QR-Only",255,0,6,6,27,6,1,0,0,"Header Text","","4","4","A4","your-domain.com/")

QR-Helix
ldata(10, 8, 25.65,28.7, 29.3, 25.8, 1.0, 1.0, 2.5, 1.0,"QR-Helix",255,0,6,6,22,6,1,0,0,"Header Text","","4","4","A4","your-domain.com/")

(Suitable especially for Lenovo Helix to place it on the inside of the serial number and fcc cards you can pull out of the helix - Great thing is that people won't remove it, since they don't see it :D at that place when the cards are pushed back into the device.)