Adds the FurnaceSmeltingEvent calls and functions to the Furnace API.
- Allows for getting/setting the cook time
- Allows for cancelling the Smelting event
- Continues to burn fuel even if smelting event is cancelled

Signed-off-by: The Yeti <admin@theyeticave.net>
Merge pull request #27 from TheYeti/master

FurnaceSmeltingEvent