Bug#733049: debian-installer does NOT add bootable flag in guided partitioning mode

[Andres Cimmarusti <acimmarusti@gmail.com>]

> Isn't this flag supposed to be more or less decorative these days?
>
> (IOW: what's your particular setup, why does it need this flag?)

I'm always working with old computers. They don't have a separate EFI
partition (most of them can't handle it anyways) and usually I choose
to install GRUB in the root partition, thus I need to make it
bootable. I assure you there's nothing decorative about it in these
systems. When I first tried wheezy in one of these computers, I kept
getting unbootable installations, and finally I saw that ticking on
the bootable flag did the trick.

> And what do you propose for this? :-)

I propose this be re-enabled by default on the guided partitioning if
the debian installation media is NOT booted in EFI mode. Unless I'm
grossly misunderstanding the issue as I explained above.