Adress-Class implemented, can hold adress-information
Adress added to Customer, so that you can Save the Adress-Information
about an Customer
Kimai_Database_Mysql->getCustomers adds an Adress-Object to the
Customer-Instances
Adress->toString returns an String with all the stored information
Customer->toString returns all stored informatione formated through HTML
(just for developement)
Added Code-Comments to Customer
Code-Comment-Format for author-property for Customer-Class
Added Code-Comments to the Adress-Object
Corrected some Code-Comments in the Customer-Object