*   Add Tag support: suffix-octothorpe, infix-comma, infix-semicolon (GH-53)
*   Remove previously deprecated NoopClient. Use a nil `*Client` Statter as a
    replacement, if needed. Ex:
    ```
    var client Client
    // A nil *Client has noop behavior, so this is safe.
    // It will become a small overhead (just a couple function calls) noop.
    err = client.Inc("stat1", 42, 1.0)
    ```
*   bump major ver