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]]}]}

Resources/Textures/Objects/light_bulb.rsi/meta.json

@@ -0,0 +1,44 @@
+{
+    "version": 1,
+    "size": {
+        "x": 32,
+        "y": 32
+    },
+    "license": "CC-BY-SA-3.0",
+    "copyright": "Taken from https://github.com/discordia-space/CEV-Eris at commit ad7c8621e5567b1b3b2b609f699b3b80cca785f2",
+    "states": [
+        {
+            "name": "normal",
+            "select": [],
+            "flags": {},
+            "directions": 1,
+            "delays": [
+                [
+                    1.0
+                ]
+            ]
+        },
+        {
+            "name": "burned",
+            "select": [],
+            "flags": {},
+            "directions": 1,
+            "delays": [
+                [
+                    1.0
+                ]
+            ]
+        },
+        {
+            "name": "broken",
+            "select": [],
+            "flags": {},
+            "directions": 1,
+            "delays": [
+                [
+                    1.0
+                ]
+            ]
+        }
+    ]
+}