Implement bokeh as alternative plotting lib

[mmaelicke]

I am thinking about implementing bokeh as an alternative for plotting. Similar to holoviews, the user could switch from the default matplotlib plotting backend to bokeh. Plotting tools would return the bokeh.plotting.figure.Figure to let the user decide whether to use it in a notebook, save it into a file or create the Jsonfor bokehjs from it. Similar to matplotlib, the functions would also accept a bokeh.Figure to plot on as an argument.

I think it is still not too much work to go for this way. Would help the lib, and might be helpful in V-FOR-WaTer portal. @MarcusStrobl , what do you think about this?

Would it be appreciated and helpful in the Visualization implementation of V-FOR-WaTer?