Add mesecons support for the rest of the other relevant lights

Each light connects only according to what sides make sense.

For example:

* a plasma lamp cube or large lattice lamp will connect from all 6 sides
* a ground lantern will only connect from its NSEW sides, not its top or
  bottom
* a glowlight slab, glowlight cube, or lattice cube uses the same rules as
  mesecons lamps, so its four edges and it back/bottom, whatever its
  orientation, but not its top/front.
* a (kitchen) ceiling lamp, and a (hanging, exterior) ceiling lantern will
  only connect from the top.

Rope lights are defined as a conductor, just like a mesecons wire,
so if mesecons is present, they will default to off unless powered by
a mesecons wire/switch/etc.

You can still right-click-toggle individual segments on/off.

Ceiling rope light connection rules are a little funky, but they work
(I wanted them to only connect from the top, but I couldn't get it
just right).  Floor-orientation connections are straightforward.