ZFS bootable pool detection code strictness

[Volodymyr Kostyrko]

Hi all.

First of all thank you for working on ZFS support. ZFS stability is 
unmatchable and I'm heavily relying on ZFS right now.

Last bootcode updates had given me some fun time. My pool contains some 
vdevs with skein enabled so new bootcode forced my pool out of boot. I 
know that my hands are dirty but I'm sure the pool is bootable as 
everything required for booting was never touched by unsupported options 
(I know the boot will fail instantly). Yes, I do like experimenting a lot.

 From my point of view the code committed is just too strict locking out 
anyone who tries to play with extra pool properties. The analyzer itself 
is nice and I don't want it to go away as every extra bit of information 
about why boot may fail is precious but I'd be very happy to have some 
loader knob to disable the pool blacklisting so that the code will test 
the pool, will report everything it finds unsuitable but would allow a 
booting attempt.

Thanks in advance.

-- 
Sphinx of black quartz judge my vow.