资 源 简 介
比较两个目录（包含子目录）并更新
1、发现目标目录缺少文件，则更新
2、发现目标目录的文件与源文件不同，则更新
3、更新时，保持与源目录结构相同-compare two directories (including subdirectories) and an update, the target directory lack of documentation, update 2, the target directory file with the source file were different, Update 3, update, and maintain the same source directory structure
