Update todo hours independently

[mrry550]

wbloom- My team started using this and found that when we update the actuals, the to do remains the same. When you update them in Rally proper, it subtracts from the remaining To Do time, so it would be optimal to mimic that logic.

It would be great to also be able update the To Do hours up or down as needed independently, to the use case described by David.

[mrry550]

Updated on 9/18