updated minimum PHP version to 5.3.3

5.3.3 has some interesting fixes and this is the version used by Redhat 6 and Debian 6

Author: fabpot

composer.json

@@ -16,7 +16,7 @@
  }
  ],
  "require": {
- "php": ">=5.3.2"
+ "php": ">=5.3.3"
  },
  "autoload": {
  "psr-0": { "Symfony\\Component\\Filesystem": "" }