title: How to generate translation file (.po, .xliff, .yml,...) from a Symfony2/Silex project?
body: <p>Im going to build a Silex/Symfony2 project and I have been looking around for a method to generate XLIFF/PO/YAML translation files based on texts-to-be-translated inside the project but not found any instruction or documentation on it.</p>
  
  <p>My question is: <strong>Is there an automated way to generate translation file(s) in specific format for a Symfony2/Silex project?</strong></p>
  
  <p>If yes, please tell me how to generate the file then update the translation after that.</p>
  
  <p>If no, please tell me how to create translation file(s) then adding up more text for my project? I am looking for an editor desktop based or web-based instead of using normal editor such as Transifex, GetLocalization (but they dont have option to create a new file or add more text)</p>