Prefix bootstrap-3 *.less with bk-
Make widgets not interact with parent webapp
Add bokeh-widgets class to plot_context.coffee
Remove one import and one in glyphs/taylor_server
Use ECO template in preview_save_tool.coffee
Remove unneeded bootstrap 3 JS files
Prefix everything with bk- in bootstrap's JS files
Remove old bootstrap from bokehjs
Use ECO template in embed_tool and object_explorer_tool
Update modal template to bootstrap 3
Use bk- prefix in modal templates