Adds small lights and small light bulbs. (#156)

In the future, someone might want to edit the sprites so the bulb is white and not yellow.
Here's some screenshots:
![image](https://user-images.githubusercontent.com/6766154/54878560-d9242e80-4e2e-11e9-8fde-39ae082f34b0.png)
![image](https://user-images.githubusercontent.com/6766154/54878572-f3f6a300-4e2e-11e9-95a1-253a5504922f.png)

Resources/Textures/Buildings/light_small.rsi/meta.json

@@ -0,0 +1 @@
+{"version": 1, "size": {"x": 32, "y": 32}, "license": "CC-BY-SA-3.0", "copyright": "https://github.com/discordia-space/CEV-Eris/blob/2b969adc2dfd3e9621bf3597c5cbffeb3ac8c9f0/icons/obj/lighting.dmi", "states": [{"name": "broken", "directions": 4, "delays": [[1.0], [1.0], [1.0], [1.0]]}, {"name": "burned", "directions": 4, "delays": [[1.0], [1.0], [1.0], [1.0]]}, {"name": "empty", "directions": 4, "delays": [[1.0], [1.0], [1.0], [1.0]]}, {"name": "off", "directions": 4, "delays": [[1.0], [1.0], [1.0], [1.0]]}, {"name": "on", "directions": 4, "delays": [[1.0], [1.0], [1.0], [1.0]]}]}