Avoid deprecated functions from Gtk-3.4 and Gtk3.10
Prevent "doesn't implement NSApplicationDelegate" error

When building with OSX 10.6 and later.
Bug 707803: Suppress adjacent separators

Also separators at the beginning or end of a menu, especially when 
they result from moving an entry to a different menu.
Bug 707882 - App menu shows "About", "Hide", "Quit",

but does not append app name as expected.
Append the app name to the menu items.
Fix missing localization of "Help" in the main menu bar.