Fixes

Two fixes.

The one about changing the way that we get errors, I should have noticed in testing but because of the way I changed the update function to only enter into `getResourceFromThreadIfAvailable` if it was running, we weren't getting errors from the thread anymore.

The other one, I don't have an old love2d binary to test this with but I think that this might be an old issue. If you never put anything in the pending queue, `resourceBeingLoaded` doesn't get initialized and so neither of the conditions in `update` are ever true and the thread never finishes and exits.