Fix to bokeh Overlay plot handling
Fix to bokeh Overlay plot handling

basnijholt/holoviews,ioam/holoviews,mjabri/holoviews,vascotenner/holoviews,ioam/holoviews,ioam/holoviews,mjabri/holoviews,mjabri/holoviews,basnijholt/holoviews,vascotenner/holoviews,basnijholt/holoviews,vascotenner/holoviews