Set file flag to UTF-8 when zipping files. (#564)
Set file flag to UTF-8 when zipping files. (#564)

ZipArchive set default file flag as 0, which will cause file name garbled characters when decompressed by third-party tools. 
stephanheilner/ZipArchive,soffes/ssziparchive,ZipArchive/ZipArchive,ZipArchive/ZipArchive,ZipArchive/ZipArchive,soffes/ssziparchive,soffes/ssziparchive,stephanheilner/ZipArchive