Update to use the new TEI editor

.gitignore

CHANGES.md

editor/jinja2/editor/edit.jinja2

editor/static/editor/css/app.css

editor/static/editor/css/tei-editor.css

editor/static/editor/js/tei-editor.js

gulpfile.js

package.json

scripts/tei-editor/config.js

theme/_aria-menu.scss

theme/_generic.scss

theme/_header.scss

theme/_help.scss

theme/_icons.scss

theme/_loading.scss

theme/_main-menu.scss

theme/_tei-editor.scss

theme/_tree-view.scss

theme/app.scss

yarn.lock