Added imshow_active_cells!
Added imshow_active_cells!

landlab/landlab,cmshobe/landlab,laijingtao/landlab,Carralex/landlab,laijingtao/landlab,cmshobe/landlab,csherwood-usgs/landlab,amandersillinois/landlab,ManuSchmi88/landlab,landlab/landlab,SiccarPoint/landlab,Carralex/landlab,SiccarPoint/landlab,csherwood-usgs/landlab,RondaStrauch/landlab,decvalts/landlab,ManuSchmi88/landlab,RondaStrauch/landlab,RondaStrauch/landlab,decvalts/landlab,Carralex/landlab,landlab/landlab,amandersillinois/landlab,cmshobe/landlab,ManuSchmi88/landlab