all: Add filesystem notification support

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3986

vendor/manifest

@@ -446,6 +446,14 @@
 			"branch": "master",
 			"notests": true
 		},
+		{
+			"importpath": "github.com/zillode/notify",
+			"repository": "https://github.com/zillode/notify",
+			"vcs": "git",
+			"revision": "54e3093eb7377fd139c4605f475cc78e83610b9d",
+			"branch": "master",
+			"notests": true
+		},
 		{
 			"importpath": "golang.org/x/crypto/bcrypt",
 			"repository": "https://go.googlesource.com/crypto",