[syslinux] SYSLINUX 3.81-pre10

[H. Peter Anvin]

I have just pushed out Syslinux 3.81-pre10.  This fixes some pretty
serious bugs, including the fact that, apparently, isohybrid didn't work
at all in CBIOS mode.

Unfortunately it means that the isohybrid handover protocol has changed,
and so a new isolinux.bin isn't compatible with an old isohybrid or vice
versa (as a result, the magic number has changed.)

	-hpa