remove ref-counting Gc<T>#256

Merged

brson merged 3 commits intorust-lang:masterfrom

pnkfelix:fsk-remove-refcounting-gc-of-t

Oct 1, 2014

Commits on Sep 22, 2014

first draft.
pnkfelix
committed

Commits on Sep 24, 2014

Add appendix with example illustrating why `Gc` and `Rc` are not equiv.
pnkfelix
committed

Commits on Sep 25, 2014

Include output printed from the example in the appendix.
pnkfelix
committed