Apply the state of status bar visibility to the menu item

[1024]

Now just "toggle status bar" is used.

[1024]

Apply current window states to main menu items (resolve #17)

→ <<cset 9e880e6b3f76>>

[1024]

Change the timing to update menu bar item states (ref #17)

→ <<cset 2d92db25c79c>>