'error LNK2001:unresolved external symbol' when using codecvt, char16_t.

[surinkim]

When compile echoserver project, I got below link error.
(Visual Studio 2015 Update3 version 14.0.25424.00)

1>scy_base_094d.lib(filesystem.obj) : error LNK2001: "__declspec(dllimport) public: static class std::locale::id std::codecvt<char16_t,char,struct _Mbstatet>::id" (__imp_?id@?$codecvt@_SDU_Mbstatet@@@std@@2V0locale@2@A) 

This is an already reported issue to microsoft, however, it seems like that it's still not fixed in update3 lately.
link1
link2

After reading above articles, I've modified std::string trnascode(const sd::string& path) function a little bit, and I've tested that compile/execution echoserver have no problem.

Could you check this pull request? #90

Thank you for your time.

[surinkim]

I've closed this issue because it has fixed by merging #90 pull request.