Fix to PSR standart, fix tokenizer, fix function executor.

Changes:

1. Add PHP 5.3 support (Remove create arrays as `[ ]`)
2. Fix to PSR standard with use (php-cs-fixer)
3. Fix add functions.
Before:

```php
// Only support

$executor->addFunction(new Func('abs', function($a){ return abs($a); }));
```

After:
```php
$executor->addFunction('abs', function($a) { return abs($a)});

// Or

$executor->addFunction(new Func('abs', function($a){ return abs($a); }));

// Or

$executor->addFunction('my_func', array($myObject, 'methodCallable'));
```
4. Fix call function. (`call_user_func`)
5. Add functions for control varibale:
- setVars - set new variables with clear old
- removeVar - remove variable by name
- removeVars - remove all vars
6. Add `__clone` method for reset object.
7. Fix application structure
8. Normalize PHPUnit tests

Thank.