Huffman code dictionary generator

使用huffmandict函数对《小时代》进行编码，计算了整个编码的平均码长、最大码长、信息熵、编码效率的值-Use huffmandict function small time to encode the entire computing average code length coding, the maximum code length, information entropy coding efficiency value

huffman函数补充，现有的huffman缺少的huffmandict函数-huffman function complements existing huffman missing huffmandict function

Huffmandict, Huffmanenco, Huffmandeco functions in MATLAB.