Add automatic calculations for ideal water consumption volume.

[guidomz]

The app asks for age, height and gender and instead of automatically calculating for an ideal water consumption level based on these info and readily available medical standards, it asks this value from the user, who may never have an idea how to make the estimate. It renders the user-supplied data virtually unused. Aside from the mentioned user-supplied data, the app can also ask (perhaps optionally) for the person's general location characteristics (temperate, tropical, dessert, frigid, etc), activity (if he does workouts and how much time), usual clothing (light, medium, heavy), and base calculation adjustments from these.