Tokens update

Rewrite Tokens class - split it info Token class for single token and Tokens as a collection of Token items.

1. Due to some letest changes Tokens class has too many static function, and Tokens class should not be package of independent functions. Let write this more OOP way and not need to grab index of token to test it for somethink - just test token itself.
2. Grab some Tokens logic from Fixers class into Tokens class.
3. Atomize and prepare for rewriting other fixers to take advantage of Tokens class - due to some reported bugs that need to rewrite fixers in "tokens way".
4. Some litte imprs.

Is there any guide for this for Symfony? I saw only to put properties before methods. No info about static stuff.

I use to put properties/methods in order:
- static properties
- magic static methods
- static methods
- instance properties
- magic instance methods
- instance methods