reduce dependencies to actual necessary packages

Author: havvg

composer.json

@@ -15,14 +15,18 @@
   },
 
   "require": {
-    "symfony/symfony": "^2.8.2",
+    "symfony/framework-bundle": "^2.8.2",
     "symfony/propel1-bridge": "2.7.x-dev",
-    "propel/propel1": "^1.6.8",
-    "symfony/security-acl": "@stable"
+    "propel/propel1": "^1.6.8"
   },
   "require-dev": {
+    "phpunit/phpunit": "^4.8.21|^5.0.10",
+    "symfony/symfony": "^2.8.2",
     "sensio/framework-extra-bundle": "^3.0.2",
-    "fzaninotto/faker": "^1.5",
-    "phpunit/phpunit": "^4.8.21|^5.0.10"
+    "fzaninotto/faker": "^1.5"
+  },
+
+  "suggest": {
+    "symfony/security-acl": "For using the Propel ACL implementation"
   }
 }