SVR4 emulation

[Matthew Dillon]

    UFS has historically not been able to handle filesystems larger then 1TB
    due to internal arithmatic overflows.  Weird things would happen.  I 
    don't know if FreeBSD fixed those issues ... we brought in most of the
    FreeBSD 64 bit fixes for UFS, but not the 64 bit block numbers yet.

    My personal feeling is that if we want 64 bit block support we need to
    make a repository copy of the UFS code and call it something else,
    like 'ufs64' or something (ufs2 ?), rather then trying to integrate the
    support into the existing UFS filesystem.

					-Matt