updated ChangeLog for multiple subsamples with sample-reads-randomly
updated ChangeLog for multiple subsamples with sample-reads-randomly

kdmurray91/khmer,jas14/khmer,F1000Research/khmer,Winterflower/khmer,kdmurray91/khmer,F1000Research/khmer,souravsingh/khmer,jas14/khmer,souravsingh/khmer,jas14/khmer,kdmurray91/khmer,ged-lab/khmer,F1000Research/khmer,ged-lab/khmer,souravsingh/khmer,Winterflower/khmer,ged-lab/khmer,Winterflower/khmer