Improved bokeh json patch computation
Improved bokeh json patch computation

Improved code that tidies up bokeh json patches to update plots.
Should result in an overall reduction of 30-50% in the json size

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