A request from @jcjohnson that's pretty reasonable, needs to be implemented

Having to feed Variables as input to Modules is somewhat annoying, especially since DataLoader provides Tensors. On the one hand explicitly constructing variables makes it clear that Tensors and Variables are different beasts, but on the other hand it is a bit of syntactic noise that shows up in a lot of places. Would it be a terrible idea to have the forward method of a Module autowrap input Tensors into Variables?