message: Fixed reverse tabbing for tags input (mac), closes
diff: //
  import Cocoa
  +import Carbon.HIToolbox
  protocol AddTagButtonDelegate: class {
  func shouldOpenTagAutoComplete(with text: String)
  @@ -17,7 +18,7 @@ final class AddTagButton: NSButton {
  // MARK: Variables
  weak var delegate: AddTagButtonDelegate?
  - private let ignoreKeys = ["\t", " "] // Tab and space
  + private let ignoreKeys = [kVK_Tab,kVK_Space] // Tab and space
  // MARK: Override
  @@ -25,7 +26,7 @@ final class AddTagButton: NSButton {
  super.keyDown(with: event)
  // Open the auto complete if the key isn't ignore key
  - guard let characters = event.characters, !ignoreKeys.contains(characters) else { return }
  + guard let characters = event.characters, !ignoreKeys.contains(Int(event.keyCode)) else { return }
  // Replace "enter" with empty string if need
  let text = characters == "\r" ? "" : characters
  