Made histogram::show() a virtual function so that it will use the re-defined get() function in rdf class.
Made histogram::show() a virtual function so that
it will use the re-defined get() function in rdf class.


bjornstenqvist/faunus,mlund/faunus,mlund/faunus,bjornstenqvist/faunus,mlund/faunus,gitesei/faunus,gitesei/faunus,gitesei/faunus,bjornstenqvist/faunus