Temporary fix to ensure extensions have access to ImmutableMultimap. The current approach for creating jarjar'd extensions isn't going to work as cleanly as I'd originally hoped because jarjar vacuums out dependencies unused by Guice.

git-svn-id: https://google-guice.googlecode.com/svn/trunk@717 d779f126-a31b-0410-b53b-1d3aecad763e
diff --git a/common.xml b/common.xml
index 643cddd..8b0a7c6 100644
--- a/common.xml
+++ b/common.xml
@@ -119,6 +119,7 @@
       <rule pattern="net.sf.cglib.**" result="com.google.inject.internal.cglib.@1"/>
       <rule pattern="org.objectweb.asm.**" result="com.google.inject.internal.asm.@1"/>
       <keep pattern="com.google.inject.**"/>
+      <keep pattern="com.google.common.collect.ImmutableMultimap"/>
     </jarjar>
   </target>