UPGRADE FROM 2.2 to 2.3

When upgrading Symfony from 2.2 to 2.3, you need to do the following changes to the code that came from the Standard Edition:

The debugging tools are not enabled by default anymore and should be added to the web/app_dev.php front controller manually, just after including the bootstrap cache:
```
 use Symfony\Component\Debug\Debug;

 Debug::enable();
```
You also need to enable debugging in the app/console script, after the $debug variable is defined:
```
 use Symfony\Component\Debug\Debug;

 if ($debug) {
     Debug::enable();
 }
```
The parameters.yml file can now be managed by the incenteev/composer-parameter-handler bundle that comes with the 2.3 Standard Edition:
- add "incenteev/composer-parameter-handler": "~2.0" to your composer.json file;
- add /app/config/parameters.yml to your .gitignore file;
- create a app/config/parameters.yml.dist file with sensible values for all your parameters.
It is highly recommended that you switch the minimum stability to stable in your composer.json file.
If you are using Apache, have a look at the new .htaccess configuration and change yours accordingly.
In the app/autoload.php file, the section about intl should be removed as it is not needed anymore.

You can also have a look at the diff between the 2.2 version of the Standard Edition and the 2.3 version.