Added Save as PNG image file to all graphs.
Added Save as PNG image file to all graphs.

ptrd/jmeter-plugins,ptrd/jmeter-plugins,Sausageo/jmeter-plugins,ptrd/jmeter-plugins,ptrd/jmeter-plugins,Sausageo/jmeter-plugins,ptrd/jmeter-plugins,Sausageo/jmeter-plugins,Sausageo/jmeter-plugins,Sausageo/jmeter-plugins