Exploit parallerisation by applying function on individuals regardless of species

[hrlai]

If we could change the functions to calculate competition, recruitment etc. across individuals regardless of what species they are (i.e., remove the need for the sp argument), then the parallel for-loops do not need to wait for one species to complete before going over another species. This should in principal increase the sim speed, and will be even more advantageous when we have more focal species in the near future.