Simple menu system updates

Simple menu system updates

Hi,

I'm attaching a patch to Syslinux dealing with a handful of issues that
were preventing me from using the simple menu interface.  Issues covered:

* Enable "MENU ONERROR" as a keyword on par with "ONERROR".
* Enable hidden menu entries to be used as ontimeout and onerror entries
(probably the least estheticalla pleasing part, sorry about that.)
* Make global "IPAPPEND" directives apply also when using menu.c32.
* Memory allocation fix for the ontimeout-variable (unlabel does free()).
* Make menu.c32 add ipappend options at end of kernel commend line, as
pxelinux generally does.

I see 3.30-pre1 is out now, I haven't had time to check applicability of
these patches towards this.  Hope they can still be of use.

--

							Arne.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>