Raster __getitem__ now more consistent with Columns
Raster __getitem__ now more consistent with Columns

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