Issue #20. Corrected Extra Amount Node in OsStudios_PagSeguroApi_Model_Payment_Method_Api_Xml class where extra amout node sometimes is empty.
Issue #18. The item description must have 100 characters only.
Issue #11. Sometimes the shipping address does not exists. Now if shipping address does not exist the billing address is used.
Issue #10. Sometimes the class OsStudios_PagSeguroApi_Model_System_Config_Source_Config throws an offset error in public method getNodeByAttribute.
Many implementations and bugfixes.
Minor bugfix.