Output either probabilistic or binary network

[TanyaS08]

Not sure if there is philosophical value in this but it might be nice to give a user the choice to output either the binary or probabilistic network after downsampling.

Since the link distribution approach essentially creates a probabilistic value for each link which is then sampled via SpeciesInteractions random draw function it might be possible to specify which type of network should be outputted...

I think the easiest way to do this is to have the user specify in the function which type of output they want. BUT it does add the interesting question if one can have additional arguments in a function that then require other arguments...