fix some bugs
fix some bugs

and introduce a new distance metric:
two histograms may have a big distance based on the other
metrics but still have a similar shape which is what we are looking for

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb