Make bazel build fully hermetic

We no longer reference @bazel_tools//third_party. All of our transitive
dependencies are now specified explicitly in our WORKSPACE file.

I also fixed the way that jar dependencies are exported, so we don't
break strict dependency checking.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=116421176

java/com/google/domain/registry/tools/server/BUILD

@@ -26,5 +26,6 @@ java_library(
         "//third_party/java/jsr305_annotations",
         "//third_party/java/jsr330_inject",
         "//third_party/java/objectify:objectify-v4_1",
+        "//third_party/java/servlet/servlet_api",
     ],
 )