(svn r3322) - Fix: Network window crash when it receives invalid information for example from the integrated nightly, so validate the network-input when it is received

- CodeChange: added str_validate(char *str) function that checks if a string contains only printable characters and if not, replaces those characters by question marks. Also move IsValidAsciiChar() to string.h

string.c

@@ -57,3 +57,9 @@ char* CDECL str_fmt(const char* str, ...)
 	if (p != NULL) memcpy(p, buf, len + 1);
 	return p;
 }
+
+void str_validate(char *str)
+{
+	for (; *str != '\0'; str++)
+		if (!IsValidAsciiChar(*str)) *str = '?';
+}