- Pooling methods now underscored or removed:

- Pooling methods now underscored or removed:

    Pool.create_connection() -> Pool._create_connection()
    Pool.do_get() -> Pool._do_get()
    Pool.do_return_conn() -> Pool._do_return_conn()
    Pool.do_return_invalid() -> removed, was not used
    Pool.return_conn() -> Pool._return_conn()
    Pool.get() -> Pool._get(), public API is Pool.connect()
    SingletonThreadPool.cleanup() -> _cleanup()
    SingletonThreadPool.dispose_local() -> removed, use conn.invalidate()

[ticket:1982]