make buildworld .. 4.5 to 4.8

[Jeff MacDonald]

Hi,

I have an older machine that was recently turned over
to me for administration. It's running Fbsd 4.5 right
now and is a product machine. Re-install is not an option.

Is it safe to do the mergemaster/makebuildworld etc. operation
on it to bring it from 4.5 to 4.8 in one step ?

I've only got experience doing it from 1 point release to
another.

Thanks.

Jeff.