More accurately emulate System 7 & MacOS 8 styling of the Menu Bar & Menu Items

[morgant]

Beyond the work done in issue #16 re:more accurately rendering windows & window controls in the style of System 7 & Mac OS 8, I've noticed that the menu bar & menu items could use some further polishing too. Specifically:

• Menu Bar:
  • The Apple menu icon has 20px left margin, but should only have 16px (presumably the same w/right margin on application menu icon)
  • Menu label icons (like the Apple & application menus) should be vertically centered, but are 1px closer to the bottom than they should be (I think this is because the icon height is divided by two, but we're not subtracting another pixel to take into account that pixels start at zero)
  • Menu labels have 16px margin between, but shouldn't
  • When a menu label is selected, it currently highlights 50% of the margin between labels, but should highlight more (so, essentially, the menu labels should overlap... if you could select two at once)
• Menu Items:
  • Menu items have too much left & right padding (looks like 20px, but should only be 14px)
  • There should only be 4px margin between a menu item's icon & text label
  • Disclosure triangles are too big (15px tall instead of 11px tall)
  • Separator lines take up full height of a menu item, but shouldn't

There are probably further issues which I haven't identified yet.