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.

pos_cash module added

The whole logic on the POS terminals should be handled by this new module. It's based on a simple data structure to keep things simple.
In the configuration form can be set up the sequence used for enumerating the receipts, the company (used for the company data on the receipt like address etc.), the logo which will be printed and the printer port the receipt printer is connected to.

All operations like adding  or removing products will be added into pos_cash.sale.lines.
Every pos_cash.sale.line appears on the receipt with a tax code. At the end of the receipt a table of taxes is printed. With this table customers can translate the tax codes from the sale.lines to the real tax.
The receipt_code + company.id is printed at the end of the receipt as a code128 type B bar code.

After 50 meters of receipt testing, the receipts look quite nice ;)

The module is available at:
http://hg.holtzberg.de/pos_cash

The next things will be:

• Adding reversal functionality 
• Adding workflow to pos_cash.sale
• Adding customer display support
• Writing a kiosk client

Modules made working with Tryton tip version

Several changes made that the modules work with the newest Tryton development version.
The automatic creation of the dependencies when a model is added to the Synchronize module has been removed. With this the synchronization tree is more slim when default values are used furthermore models can easier added via XML.

All code review issues have been applied to the code.

A new module for synching with MySQL databases is available. It provides easy creation of mapping tables. Each Tryton model that should be synched can be adapted to data structures on a MySQL server with SQL-statements. The connection can easy be replaced by other DB-2.0 API compliant connections.
The synchronize_mysql module is available at:

http://hg.holtzberg.de/synchronize_mysql

Code cleaned up and committed for reviewing

Before the codereview the code has been cleaned up tested.

• Classnames have been changed according to the _name of the models.
• Classmembers renamed according to the projects specifications
• Some methods changed to private
• Changed comments
• Whitespace removed

We will see what the review brings...