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>

vendor/vendor.json

@@ -1368,6 +1368,12 @@
 			"revision": "917f41c560270110ceb73c5b38be2a9127387071",
 			"revisionTime": "2016-03-11T05:04:36Z"
 		},
+		{
+			"checksumSHA1": "NE1kNfAZ0AAXCUbwx196os/DSUE=",
+			"path": "github.com/tstranex/u2f",
+			"revision": "d21a03e0b1d9fc1df59ff54e7a513655c1748b0c",
+			"revisionTime": "2018-05-05T18:51:14Z"
+		},
 		{
 			"checksumSHA1": "MfWqWj0xRPdk1DpXCN0EXyBCa4Q=",
 			"path": "github.com/tinylib/msgp/msgp",