Made it more obvious, that the comments in config.json have to be removed.
Added event listener
added ability to get all available modules by status (1 - enabled (loaded) or 0 - disabled)
Added a generator to flatten multi-dimensional associative arrays or objects
This can be accessed by something like:
foreach (Data::flatten($input) as $key => $value) {
    echo $key . ' => ' . $value . "<br>\n";
}
Added language files and the ability to read them
Like before "echo Message::get('headline.welcome')" would print (if the language is English) "Welcome to Silex"
- every module has its own language file (but if there are no extra strings for that module it doesn't has to serve a file)
- Message class is now the central point to access strings (like language)