Merge pull request #127 from MinGW-caffe/master

try to avoid the error "conflicting declaration 'typedef DWORD pthread_t'" etc. in MinGW
diff --git a/src/windows/port.h b/src/windows/port.h
index d78a185..8198461 100755
--- a/src/windows/port.h
+++ b/src/windows/port.h
@@ -136,6 +136,7 @@
 #endif  // _MSC_VER
 
 // ----------------------------------- THREADS
+#ifndef __MINGW32__
 typedef DWORD pthread_t;
 typedef DWORD pthread_key_t;
 typedef LONG pthread_once_t;
@@ -147,6 +148,7 @@
   localtime_s(result, timep);
   return result;
 }
+#endif
 
 inline char* strerror_r(int errnum, char* buf, size_t buflen) {
   strerror_s(buf, buflen, errnum);