• Added PPI::Element::statement object method
  
• Added PPI::Transform abstract class
  
• Sped up the 'bool' overload for PPI::Element
  
• Added PPI::Element::snext_sibling object method
  
• Added PPI::Element::sprevious_sibling object method
  
• Added PPI::Element::insert_before object method placeholder
  
• Added PPI::Element::insert_after object method placeholder
  
• Changed {elements} to {children} to match PPI::Node definitions
  
• Added PPI::Node::first_element object method
  
• Added PPI::Node::last_element object method
  
• Added PPI::Element::next_token object method
  
• Added PPI::Element::previous_token object method
  
• Added PPI::Token::Symbol::symbol object method