message: Clean up Java hacking howto initial instructions to account for new WORKSPACE.
diff: usually installed at `/Users/username/Library/Android/sdk/`. You also need
  Android SDK Build Tools 24.0.3 or newer.
  -* Check out source code and build
  +* The javadoc targets require using JDK 8.
  +
  +* Check out the source code, navigate to the Java Bazel workspace and execute
  + all test targets in the project:
  ```shell
  git clone https://github.com/google/tink
  -cd tink
  -bazel test java/...
  +cd tink/java_src
  +bazel test ...
  ```
  ## Code structure
  ### Java packages
  -* **com.google.crypto.tink** This package consists only the core of Tink,
  +* **com.google.crypto.tink** This package consists of only the core of Tink,
  including the primitive interfaces and key management APIs. Users that
  [develop their own primitives or key
  types](JAVA-HOWTO.md#custom-implementation-of-a-primitive)
  