Formatting translations into XLIFF thanks to JMSTranslationBundle. 

First attempt of formatting translations into XLIFF.

Formatted as decribed here : https://github.com/Sylius/SyliusPromotionsBundle/issues/5

A google doc to take an inventory of the translations process : https://docs.google.com/spreadsheet/ccc?key=0Ak5XCV_t5iZ0dHV6WFdDUnBwMnZ5WFVmTGZMU1J3VkE#gid=0