Add tools to bokeh plots

[harbi811]

• Resolves #414

Save and crosshair tools are added to bokeh plots.

[alimanfoo]

Thanks @harbi811, looks good. Could you check that these additional tools also appear when you call functions like plot_h12_gwss() which include both the H12 track and the genes track?

[harbi811]

Thank you @alimanfoo . The added tools appear on all plots with or without the genes track. Here are a couple of screenshots from plot_fst_gwss() and plot_fst_gwss_track()

[alimanfoo]

Thanks @harbi811, I guess this must be handled by the merging of tools from different subplots (merge_tools parameter) which is great.

[alimanfoo]

Merged, thanks @harbi811 🎆

[harbi811]

Thank you @alimanfoo 😊