eatfoodonce: eatfoodonce
In syanco/checkyourself: Simulates a simple agent-based species distribution model

Simulates a single consumption event by a consumer and returns the carbon and nitrogen values for the consumed prey. Meant to be call by 'eatfoodsteps' and 'eatfood'.

1	eatfoodonce(num_sources, diet_prop, food)

`num_sources`	integer, the number of food sources to choose from. Can not exceed the actual number of available food sources.
`diet_prop`	vector, the relative probability of selecting a source. Must have an entry for each source.
`food`	list, the simulated food sources from which to select.