说明：  lz77压缩算法单元源文件出自王咏刚先生的《笨笨数据压缩教程》中的lz77.c由崔东伟修改为pascal单元
(lz77 compression algorithm module source file from Mr. Wang Yonggang' s " simple-minded, data compression tutorial" in lz77.c by Choi Dong-wei was revised to pascal unit)