ESC/POS Display support added

The python-escpos lib from http://code.google.com/p/python-escpos/ has been extended by ESC/POS display support  and some other stuff.

Here are some pictures of how the hardware output looks like:

First product scanned
Second product scanned
Total amount
Drawback
Receipt

Thanks to the MEGA Bike corporation  which allowed me to publish the current development status of the receipts with their logo.