title: Magento - custom invoice id format
body: <p>I want to re-numbering of invoices. The renumbering should be composed as follow.</p>
  
  <p>I would like this format for invoice ID's: INV-10001-2014</p>
  
  <p>INV-00001-13; INV-00002-13; O-00003-13; ['INV' for invoice, 5 places for the number; “-“ ; current year. Next year this numbering should finish in 14 (from 2014).</p>