完成各种编码方式的文本转换为UTF8，包括ascii,ucs2,ucs4,ISO-8859-1,UTF16等类型-transcode ever code type text to utf8,include ascii,ucs2,ucs4,ISO-8859-1,UTF16

unicode编码转换为gbk码，短信传输的unicode码，单片机中存储的gbk码，做短信功能时需要转码，该程序实现转码功能，已经过验证。-gbk encoding to unicode code, SMS transmission unicode code stored in the microcontroller gbk code, do SMS functionality needed to transcode the program transcoding functionality