Take into account additional caloric need from exercise (esp. cardio)

[ysalmon]

Use case

Some exercise, especially cardio, but also walking a long walk, consume a significant amount of calories. A fraction of these calories (to take into account that the base caloric objective assumes a basic level of activity) should be added to the caloric and nutritional envelope of the day.

Proposal

It should be possible to log physical activities and the corresponding caloric expense, and have it reflected in the nutrition tab.

Since these activities may be out of a regular plan, maybe this could be integrated in the nutritional tab directly.