3.0

1. Unique values (global variable unique) no longer aim for individuality, but instead adopt a stable and universal method.
2. Adjusted the position and parameter types for validating DataValidator initialization parameters, resulting in a more structurally sound process.
3. Blueprints can now be instances of a dict subclass (changed the way blueprints are type-validated, no longer only validate the direct type of the instance).
4. Optimized blocks of code to generate mapping dictionaries for both definable and coercible types.
5. Removed optional parameter allowable_placeholder, as it is unlikely to be modified and unnecessary to modify.
6. Improved functional descriptive information and made class DataStruct uninheritable.
7. Optimized example code and build module code, including files test.py and setup.py.
8. Refactored (improved) the method used to retrieve version information in setup, directly extracting it from package.__doc__ instead of opening a file.
9. Adjust the open source library categorization information on PyPi.
10. Update the README file.

1.唯一值（全局变量 unique）不再追求个性，而是采用稳妥的通用方案。
2.调整 DataValidator 初始化参数的校验位置和参数类型，使结构性更完美。
3.创建蓝图允许是 dict 的子类实例（改变蓝图的类型校验方式，不再只校验实例的直接类型）。
4.优化代码块，生成可定义类型和可强转类型的映射字典的代码块。
5.删除可选参数 allowable_placeholder，它几乎不会被修改，也没有必要修改。
6.改进功能描述信息，并使类 DataStruct 不可被继承。
7.优化示例代码和构建模块代码，包括文件 test.py，setup.py。
8.重构（改进） setup 中获得版本信息的方案，直接从 package.__doc__ 中提取，而不再打开文件。
9.调整在PyPi上的开源库分类信息。
11.更新自述文件。