Cope with nenya's split into nenya/nenya-tools.

I should really split off a vilya-tools from vilya, but I can't be fucked to do
that when I'm already so deep in yak hair that I can't tell whether it's day or
night.

pom.xml

@@ -67,6 +67,12 @@
     </dependency>
 
     <!-- optional dependencies -->
+    <dependency>
+      <groupId>com.threerings</groupId>
+      <artifactId>nenya-tools</artifactId>
+      <version>1.5</version>
+      <optional>true</optional>
+    </dependency>
     <dependency>
       <groupId>commons-digester</groupId>
       <artifactId>commons-digester</artifactId>