OGLplus 0.55.0 发布，OpenGL 的 C++ 封装库

OGLplus 0.55.0 发布，此版本添加了 ``ClientContext`` 类，用来维护(暂时只有部分) GL 状态，允许 push/pop 独立状态变量或者是高效查询和改变他们的值。此版本同时还更新了快速入门文档；平台的移植不再至此和原始重启参数；一些 bug 修复。

改进记录

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 - The ``oglplus::ClientContext`` class was added.

 - The ``EnumToClass`` template and its specializations were added.

 - A new getter/setter functions were added to ``oglplus::Context``.

 - A bug in ``Texture::Active`` was fixed.

 - Some of the shape builders were ported to platforms not supporting GL primitive restart.

 - The Quickbook documentation was updated.

 - Minor changes were made in the compiler configuration header.

 - One of the examples was updated to show the new features.

OGLplus (oglplus) 是一个仅包含头文件的 C++ 语言库，用于实现一个瘦面向对象的 OpenGL 门面操作接口，提供了自动资源和对象管理的封装，让在 C++ 中使用 OpenGL 更加简单和安全。