MSVC: Use the Unix emulation headers

[JES: provided commit message, split out unrelated changes]
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

libvncclient/tls_openssl.c

@@ -32,6 +32,8 @@
 #include "tls.h"
 
 #ifdef _MSC_VER
+#include <BaseTsd.h> // That's for SSIZE_T
+typedef SSIZE_T ssize_t;
 #define snprintf _snprintf
 #endif
 
@@ -308,7 +310,11 @@ return TRUE;
     if (ret != -1)
     {
       rfbClientLog("TLS handshake blocking.\n");
+#ifdef WIN32
+      Sleep(1000);
+#else
 	  sleep(1);
+#endif
       timeout--;
       continue;
     }

rfb/rfbproto.h

@@ -108,6 +108,10 @@ typedef int8_t rfbBool;
 #define TRUE -1
 #endif
 
+#ifdef _MSC_VER
+#include <stdint.h>
+#endif
+
 typedef uint32_t rfbKeySym;
 typedef uint32_t rfbPixel;