Port LinkedList<E>

[AlejandroLoutphi]

New methods to be added:

• [x] void addAtHead(E elt)
• [x] A way to iterate over the list in a for loop (maybe we can already do this with the existing class, idk)

[AlejandroLoutphi]

To iterate over the list with a for loop, do

for (LinkedListNode<E> i = theListToIterateOver; i != null; i = i.getNext()) {
    thing = i.getElt();
    //do stuff with thing
}

Replace E with whatever type the list has

[AlejandroLoutphi]

Done, see results in 2-box