Allow embedded applets to be cached indefinitely by proxies

If we embed a Java applet into the WAR its probably a decent sized
download.  We should make it available as a cached entity that will
never expire, so proxies and browser caches can retain it for quite
a long time.

Signed-off-by: Shawn O. Pearce <sop@google.com>

src/main/java/com/google/gerrit/server/CacheControlFilter.java

@@ -69,6 +69,9 @@ public class CacheControlFilter implements Filter {
     if (pathInfo.endsWith(".cache.png")) {
       return true;
     }
+    if (pathInfo.endsWith(".cache.jar")) {
+      return true;
+    }
     return false;
   }