sagews: add support for matplotlib's imshow
sagews: add support for matplotlib's imshow

DrXyzzy/smc,DrXyzzy/smc,sagemathinc/smc,sagemathinc/smc,sagemathinc/smc,tscholl2/smc,DrXyzzy/smc,DrXyzzy/smc,tscholl2/smc,sagemathinc/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc