Fixes the issue with line number when parsing several files

Hi guys,

I found excellent, well... quite excellent, but I was really annoyed about the issue with the line numbers when excellentizing several files at once.

Example:
Assuming that I used the snipped of the README:
```
class ShoppingBasket < ActiveRecord::Base
  def initialize(items = [])
    self.items = items
  end
end
```
And copy/paste it in 3 files r1.rb, r2.rb and r3.rb in the folder test, the command:
```
excellent test/
``` 
would return:
```
  Excellent result:

  test/r1.rb
    * Line   1: ShoppingBasket does not specify attr_accessible.
    * Line   1: ShoppingBasket does not validate any attributes.
    * Line   1: ShoppingBasket defines initialize method.

  test/r2.rb
    * Line   6: ShoppingBasket does not specify attr_accessible.
    * Line   6: ShoppingBasket does not validate any attributes.
    * Line   6: ShoppingBasket defines initialize method.

  test/r3.rb
    * Line  11: ShoppingBasket does not specify attr_accessible.
    * Line  11: ShoppingBasket does not validate any attributes.
    * Line  11: ShoppingBasket defines initialize method.

  Found 9 warnings.
```

By resetting the parser, we now have a results with corrects line numbers:

```
  Excellent result:

  test/r1.rb
    * Line   1: ShoppingBasket does not specify attr_accessible.
    * Line   1: ShoppingBasket does not validate any attributes.
    * Line   1: ShoppingBasket defines initialize method.

  test/r2.rb
    * Line   1: ShoppingBasket does not specify attr_accessible.
    * Line   1: ShoppingBasket does not validate any attributes.
    * Line   1: ShoppingBasket defines initialize method.

  test/r3.rb
    * Line   1: ShoppingBasket does not specify attr_accessible.
    * Line   1: ShoppingBasket does not validate any attributes.
    * Line   1: ShoppingBasket defines initialize method.

  Found 9 warnings.
```

Yay !

Keep up the good work, guys, and thank you for excellent !