[syslinux] SYSLINUX 3.07-pre1: chainloading fix

[H. Peter Anvin]

I will not push half-finished features into production.
I will not push half-finished features into production.
I will not push half-finished features into production.

I have pushed out syslinux-3.07-pre1; this should have a fix for the 
chainloading problem.  It actually turned out to be multiple problems, 
some of which makes me believe chain.c32 probably hasn't worked since 
2.12 or so.

Please test this out, including if there is anything else that we can fix...

	-hpa