Marked Spout dependencies as optional.

pom.xml

@@ -89,11 +89,13 @@
       <groupId>org.spout</groupId>
       <artifactId>spoutapi</artifactId>
       <version>dev-SNAPSHOT</version>
+      <optional>true</optional>
     </dependency>
     <dependency>
       <groupId>org.spout</groupId>
       <artifactId>vanilla</artifactId>
       <version>1.3.0-SNAPSHOT</version>
+      <optional>true</optional>
     </dependency>
   </dependencies>