Allow light fixtures to be installed anywhere

[Zamujasa]

Currently, you can only install light fixtures on walls. This means that you can't install them against anything else, or glass.

Suggestion:
- Clicking an adjacent turf, or an object on that turf, installs a lighting fixture on your turf, against that one (like clicking on walls does right now)
- Clicking on your turf directly installs a "floor" fixture, like the small circular ones in Clarion's bar and occasionally elsewhere -- would need new tube sprites, but would let you manufacture floor lights

This would also allow people to make new lighting in areas that are otherwise impossible to light up (Biodome, some other places).

[cyberTripping]

The floor dome lights could probably just use the already-implemented lightbulbs, since that's typically what dome lights use irl. Never actually seen lightbulbs used, to the degree im unsure what their intended use is.

[Zamujasa]

The floor lights already use regular lightbulbs, but you can't build the fixtures themselves.