Remove json3 dependency
Merge pull request #821 from nlegoff/remove_json3

[3.9] Remove json3 dependency
Update symfony 2.4 to latest commit
Fix route generation parameters
Fix tests
Update to symfony 2.4.0
Fix twig tags
Use TranslationServiceProvider, fix use of form_div_layout
Update templates to fit the new translator
Remove old tests
Use symfony translator
Add JMS translation tools
Move locales to resources folder
Cleanup po resources
Locale simplification
Fix translation dumper
Use xliff instead of po files
Add cached translation loader
Fix unit tests and arrays declaration
Bump to version 3.9.0-alpha.9