add new function 'reduceBy' to support creating a new object with the same set of keys the specified source object but with values altered via caller callback executed for each key, behavior mimics  js array 'reduce' function

add new 'get' function as a shorthand method for retrieving the closure function to access the data object

add additional parameter to the 'promiseTimed' function to support a cancellation event that can immediately preempt the executing promise when triggered, returns a resolved promise with a void value, or a default value if specified