Do not make use of the List class as it does not have the each method
Extracted method _isStandAloneToken
Renamed _StandAloneLineCapable to StandAloneLineCapable
Simplified the line#_isStandAloneToken method
Added another line test and removed old one
Simplified line tests by providing a factory method
Added a toString method to the _CommentsToken
Added some more Line tests and simplified the Line#_isEndOfLine method