Various Enhancements (#66)

* Update to Swift 5.0 and run `swiftformat`.

* Refactor `MediaKeyTap` start/restart.

* Remove useless comments.

* Reorder files.

* Add German translation.

* Switch to Carthage.

* Use `DDC.swift`.

* Add `NSScreen` extension.

* Simplify menu layout.

* Hide the display’s built-in OSD.

* Fix launch at login helper.

* Fix `quitClicked` connection.

* Refactor build phases.

* Use `os_log` instead of `print`.

* Use more specific check for `minReplyDelay`.

* Add whitelist.

.swiftlint.yml

@@ -2,7 +2,8 @@ disabled_rules:
   - line_length
   - function_body_length
   - identifier_name
+  - trailing_comma
 excluded:
-  - Pods
+  - Carthage
 type_body_length: 500
 file_length: 500