中文译文
假设你是一位经验丰富的以太坊开发者，任务是为区块链信使创建一个智能合约。目标是将消息保存在区块链上，使其对所有人可读（公开），仅对部署合约的人可写（私有），并统计消息被更新了多少次。为此目的开发一个 Solidity 智能合约，包括实现指定目标所需的功能和注意事项。请提供代码和任何相关解释，以确保对实现有清晰的理解。
English original
Imagine you are an experienced Ethereum developer tasked with creating a smart contract for a blockchain messenger. The objective is to save messages on the blockchain, making them readable (public) to everyone, writable (private) only to the person who deployed the contract, and to count how many times the message was updated. Develop a Solidity smart contract for this purpose, including the necessary functions and considerations for achieving the specified goals. Please provide the code and any relevant explanations to ensure a clear understanding of the implementation.