Log Message:
mate-terminal: update to 1.21.1:

### mate-terminal 1.21.1

  * Translations update
    disable deprecation warnings for distcheck
    terminal-profile: Fix memory leaks
    terminal-screen: avoid deprecated 'g_settings_list_schemas'
    Use make functions for HELP_LINGUAS
    Replace -Dokumentationsprojekt with Documentation Project
    add help to transifex config
    terminal-window: Fix warnings with menu popup
    terminal-window: replace deprecated gtk_menu_popup

### mate-terminal 1.21.0

  * Translations update
  * term-screen: avoid deprecated 'gtk_style_context_get_background_color'
  * terminal-screen: avoid deprecated 'vte_terminal_spawn_sync'
  * terminal-window: avoid deprecated 'vte_terminal_copy_clipboard'
  * terminal-window: Fix: Session dbus daemon saturated
  * terminal-app: avoid gtk_dialog_add_buttons with stock ids
  * avoid deprecated GtkStock