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/common/io/BUILD

@@ -2,5 +2,5 @@ package(default_visibility = ["//visibility:public"])
 
 java_library(
     name = "io",
-    exports = ["@bazel_tools//third_party:guava"],
+    exports = ["@guava//jar"],
 )