Add support for FIDO U2F (#3971)

* Add support for U2F

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add vendor library
Add missing translations

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Minor improvements

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add U2F support for Firefox, Chrome (Android) by introducing a custom JS library
Add U2F error handling

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add U2F login page to OAuth

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Move U2F user settings to a separate file

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add unit tests for u2f model
Renamed u2f table name

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Fix problems caused by refactoring

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add U2F documentation

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Remove not needed console.log-s

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add default values to app.ini.sample
Add FIDO U2F to comparison

Signed-off-by: Jonas Franz <info@jonasfranz.software>

templates/base/footer.tmpl

@@ -64,6 +64,9 @@
 {{if .RequireDropzone}}
 	<script src="{{AppSubUrl}}/vendor/plugins/dropzone/dropzone.js"></script>
 {{end}}
+{{if .RequireU2F}}
+	<script src="{{AppSubUrl}}/vendor/plugins/u2f/index.js"></script>
+{{end}}
 {{if .RequireTribute}}
 	<script src="{{AppSubUrl}}/vendor/plugins/tribute/tribute.min.js"></script>