[WIP] Fixer that converts old style constructors into __construct()

Please share your thoughts on this fixer.

I need to implement ignoring of oldstyle constructors in namespaced classes (added in PHP 5.3.3), and the fixer should be done.

I'm wodndering if there are some more rules that i should consider in this fixer?
Please ensure that `$tokens[$methodName]` is a method name indeed.
You may encounter here syntax like
```php
public function foo()
{
    $bar = function () {};
}
```

and `$bar` lambda function hasn't got any name