I tested the actual Xenial on my BPP but got a crashdump each time I reboot or shutdown the system.
I found, that armhwinfo was causing this crash by removing the module a20_tp.
Disabling the line
/sbin/modprobe -r $(cut -f1 -d' ' </proc/modules)
in /etc/init.d/armhwinfo avoid this problem.
This line is part of a patch Thomas Kaiser introduced in October last year.
I don't know, if this problem occurs only in my configuration (nothing special, but a connected Lemaker 5" LCD may be the difference), or it is related to the Kernel 3.4.113 only, but it goes reproducably wrong, if this line is active. It cause the oposite of the intention of this patch, because after the crash, the next module (sunxi_ir) is ending in a loop. So no sync is executed and the power stays on.
Without this line, all works well.
I think, the patch has to be patched again - don't touch a20_tp.
