Preparing for axTLS. Actual SSL API functions are only stubbed.

Added axTLS to autotool files and glue code to misc other files.
axtls.h maps SSL API functions, but may change.
axtls.c is just a stub file and will definitely change.

lib/http.c

@@ -1881,10 +1881,22 @@ static int https_getsock(struct connectdata *conn,
   (void)numsocks;
   return GETSOCK_BLANK;
 }
-#endif
-#endif
-#endif
-#endif
+#else
+#ifdef USE_AXTLS
+static int https_getsock(struct connectdata *conn,
+                         curl_socket_t *socks,
+                         int numsocks)
+{
+  (void)conn;
+  (void)socks;
+  (void)numsocks;
+  return GETSOCK_BLANK;
+}
+#endif /* USE_AXTLS */
+#endif /* USE_POLARSSL */
+#endif /* USE_QSOSSL */
+#endif /* USE_NSS */
+#endif /* USE_SSLEAY || USE_GNUTLS */
 
 /*
  * Curl_http_done() gets called from Curl_done() after a single HTTP request