Incompatible change from 1.0:
  generatesimulationData renamed to simulateReadCounts()

  Semantics of group parameter was changed to adhere to the semantics of edgeR.
  Now you should specify the group each sample belongs to.
  For simulateReadCounts(), replicates parameter is used to
  distiguish different semantics. This parameter accepts the number of replicates
  in each group.

  names field were changed to gene_id to be more specific nature of the field.
  Although the count unit is not limited to gene, we here call it gene_id, 
  because the unit is actually often the gene.

  hypoData are reduced to a smaller data set, so that you can readily learn how to
  use TCC. For larger data set, you can use simulateReadCounts()
