- rebuild menu when prefs change outside of systray, such as setting an
exit node
- refactor onClick handler code
- compare lowercase country name, the same as macOS and Windows (now
sorts Ukraine before USA)
- fix "connected / disconnected" menu items on stopped status
- prevent nil pointer on "This Device" menu item
Updates #1708
Change-Id: Ia101a4a3005adb9118051b3416f5a64a4a45987d
Signed-off-by: Will Norris <will@tailscale.com>