v0.6.0

• Add Intersect returns the intersection between two collections (thks @samber)
• Add Difference returns the difference between two collections (thks @samber)
• Add GetOrElse retrieves the value of the point or default (thks @samber)
• Add Subtract the subtraction between two collections. It preserves order (thks @airani)
• Fix bug in lastIndexOf (thks @kkty)