[Translation] Allow using "etc/translations" to store translations files

symfony/translation/3.3/etc/packages/translation.yaml

@@ -0,0 +1,7 @@
+framework:
+    default_locale: '%locale%'
+    translator:
+        paths:
+            - '%kernel.project_dir%/translations/'
+        fallbacks:
+            - '%locale%'

symfony/translation/3.3/manifest.json

@@ -1,3 +1,10 @@
 {
+    "copy-from-recipe": {
+        "etc/": "%ETC_DIR%/",
+        "translations/": "translations/"
+    },
+    "container": {
+        "locale": "en"
+    },
     "aliases": ["translator"]
 }