* Clean up & comment base templates
* Clean up login template & form
* Use SVG file for NetBox logo
* Simplify breadcrumbs
* Merge changelog.html into home.html
* Rename title_container block to header
* Move breadcrumbs block to object.html
* Attach names to endblock template tags
* Reorganize root-level templates into base/ and inc/
* Remove obsolete reference to Bootstrap 3.4.1