Add collections

[422404]

Add collections and built-in functions to manipulate them.

Example:

myList = newList();
listAdd(myList, 1337);
listRemove(myList, 1337);
if (listContains(myList, 42)) {
  ...
}
if (listEmpty(myList)) {
  ...
}

mySet = newSet();
...

myMap = newMap();
mapPut(myMap, "hello", 42);
mapGet(myMap, "hello");
mapRemove(myMap, "hello");
if (mapContains(myMap, "hello")) {
  ...
};
keys = mapKeys(myMap);
values = mapValues(myMap);