Tweak gormlak movement slightly

- Don't let gormlaks run into things like walls or each other
- Add a small element of randomness to gormlaks' motion
- Increase gormlaks' vision by a large amount

package.yaml

@@ -41,6 +41,9 @@ dependencies:
 - mtl
 - optparse-applicative
 - random
+- random-fu
+- random-extras
+- random-source
 - raw-strings-qq
 - reflection
 - stache