Vector#to_list doesn't reverse items. #to_list is also faster for all Enumerables

Hamster::Enumerable#to_list would previously reverse the items in a Vector or
SortedSet. Its performance was also suboptimal. ::Enumerable#to_list did not reverse
items, but its performance was also less than optimal.

The new ::Enumerable#to_list is faster than either -- it does something like Common
Lisp's NCONC. Hamster::Enumerable#to_list has been removed, so Hamster collections
will fall back to the new ::Enumerable#to_list.