plot.imshow now gives default title to plots
plot.imshow now gives default title to plots

The various plotting tools in plot.imshow now use the field name as a
makeshift title for the plot, if one was provided.

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