removed debug output about number of items to process because this is
now done in class ParallelService
adding unit testing for new 'collapse_species' option of StarBEAST
module
added new option to StarBEAST module: if collapse_species is set, forma,
subspecies and varieties are summarized into one species during the
multispecies coalescent. Until now this was the default. By disabpling
this option, we can now build trees with higher taxonomic resolution.