Increase fixtures hot water use when no dishwasher present

[shorowit]

Currently if there is no dishwasher in the home, we just exclude that gal/day of usage. But we should really increase the fixtures use by a certain amount because they'd be washing dishes by hand.

Need to identify a good data source for how much water is used when washing dishes by hand.

[shorowit]

@jmaguire1 pointed out that the FSEC paper, which is the basis for the fixtures hot water use, may already be averaged across both homes with and without dishwashers, in which case it would already include some washing of dishes by hand. So it's a little tricky.