WIP Enhance LinkedList with new methods

[vmasto]

Hello! This PR aims to add a few more helpful methods in the Linked List implementation. If you so approve we could add more and once the API is finalized I'd be happy to implement a Doubly Linked List.

I'm aware of issue #18 but I'd need a few more details on what methods you'd like to be added.

[Yomguithereal]

Hello @vmasto. Thanks for the PR. I think we need to change some things about the LinkedList before adding the move methods. I think we should make the internal node rely on some class like LinkedListNode instead of a plain object and make the push method return the instance of this class because else the move methods are O(n) rather than O(1) which is normally the real advantage of using a list rather than an array in memory. What do you think?

[vmasto]

Makes sense to use LinkedListNode, however can we spec out the move methods?

[Yomguithereal]

Sure. Just ping me back if I forget.

[vmasto]

Ping :D

[Yomguithereal]

I am still reflecting on how to change the API if we go the node class way. Because it might feel strange if some methods return a node and other ones don't.