Syslinux - Feb 2008 - SYSLINUX 3.62-pre11: hierarchial submenu support

Well, it took a lot more effort than I really wanted, but SYSLINUX 
3.62-pre11 has proper hierarchial submenu support.  This was a pretty 
massive rewrite of large parts of the simple menu system, so I fully 
expect bugs.

I would greatly appreciate any help with testing this out.

	-hpa