Windows compatibility fixes

VS2013 has trouble with relative include paths for apps/openssl, so move
certhash_win/apps_win.c back to apps/openssl.

gmtime_r on mingw64 fails with negative time_t, override

gmtime_s fails all of the time unit tests, override

SHUT_RD/WR are defined in newer mingw64 headers, check before overriding

include/compat/time.h

@@ -9,11 +9,15 @@
 #else
 #include <../include/time.h>
 #endif
-#define gmtime_r(tp, tm) ((gmtime_s((tm), (tp)) == 0) ? (tm) : NULL)
 #else
 #include_next <time.h>
 #endif
 
+#ifdef _WIN32
+struct tm *__gmtime_r(const time_t * t, struct tm * tm);
+#define gmtime_r(tp, tm) __gmtime_r(tp, tm)
+#endif
+
 #ifndef HAVE_TIMEGM
 time_t timegm(struct tm *tm);
 #endif

include/compat/win32netcompat.h

@@ -11,14 +11,19 @@
 #ifdef _WIN32
 
 #include <ws2tcpip.h>
-
-#define SHUT_RDWR SD_BOTH
-#define SHUT_RD   SD_RECEIVE
-#define SHUT_WR   SD_SEND
-
 #include <errno.h>
 #include <unistd.h>
 
+#ifndef SHUT_RDWR
+#define SHUT_RDWR SD_BOTH
+#endif
+#ifndef SHUT_RD
+#define SHUT_RD   SD_RECEIVE
+#endif
+#ifndef SHUT_WR
+#define SHUT_WR   SD_SEND
+#endif
+
 int posix_connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen);
 
 int posix_close(int fd);