*   Removed data download links from TensorBoard.
    *   TensorBoard uses a relative data directory, for easier embedding.
    *   TensorBoard automatically ignores outliers for domain calculation, and
        formats proportional values consistently.
*   Multiple tfdbg bug fixes:
    *   Fixed Windows compatibility issues.
    *   Command history now persists across runs.
    *   Bug fix in graph validation related to `tf.while_loops`.