mattpap and bryevdv Allow easy customization of HTML templates (#7708)
* Clean up axis_label_extra_x_ranges

* Add support for FILE/save() template customization

* Update plotting/file/css_classes example

* Relax conditions in LayoutDOM._calc_width_height()

* Add plotting/file/custom_layout example

* Unskip no_border_or_background_fill example

* Don't unnecessarily split resources into JS and CSS

* Rewrite app/surface3d using a custom template

* Use {% extends base %} instead of FILE

* Enable examples/embed on travis ci

* Move embed() macro to macros.html

* Add integration/embed/css_grid_simple example

* Split up src/lib/embed.ts

* Allow doc.template to be string

* Allow to use external templates

* Add integration/embed/css_grid_simple_no_extend

* Preliminary support for server support

* Flatten HTML of a root (drop bk-plotdiv)

* Finalize implementation of custom HTML templates

* Allow custom templates to modify <body> tag

* Restore notebook and autoload support

* remove +x from lone example file

* refactor a warning in bokeh.embed.util

* Update templates in examples/app

* Improved resolution when mod.js and mod/index.js both exist

* Make autoload server work again

* Don't provide elementid for server pages

* Allow to filter roots by name or tags

* Add backwards compatibility for plot_div

* Restore components({...}) functionality
Latest commit 3eaa05a Jun 7, 2018