Installer partition sizing bug

[Chris Pressey]

Thanks to all who submitted reports.

The summary is that the size of the installed-to slice is mistakenly
changed to the size of the last slice on the disk, making it unsafe to
use the installer to install DragonFly to any slice except the last.

This stemmed from an assumption I made, that 'fdisk -1 -s' would produce
a summary of slice 1 only.  I failed to adequately test this assumption,
and for that I apologize for any lost time & frustration it might have
caused.  The bug is now noted in the errata; it has been fixed, and
tested by Matt; the fdisk man page has been clarified; and a maintenance
release is forthcoming.

Thanks again,
-Chris