Lenovo BIOS boot fix

[Warren Block]

>
> Needing the active flag set is indeed a different problem. I am working
> on a patch for bsdinstall that will allow the user to request the active
> bit be set as well.

For GPT, that should be the default, because it matches the standard.

I would like to see an effort to get Lenovo to fix their broken 
UEFI/BIOS.  Adding non-standard PMBR configurations should be short-term 
hack.