Callbacks passed into promiseChain and promiseFor no longer need to return a promise - this is now done automatically.
The promiseChain callback is now passed the following arguments (see usage): resolve, reject, preceedingReturnValue
The promiseFor callback is now passed the following arguments (see usage): resolve, reject, i, preceedingReturnValue
New usage for promiseChain and promiseFor - call either resolve or reject when the callback's work is done.