HEADS UP: powerpc64 import

[Nathan Whitehorn]

Over the next week, I will be importing 64-bit PowerPC support into 
-CURRENT. While I will be trying very hard not to break things for 
32-bit systems, things will be in a little bit of flux, so upgrades in 
-CURRENT should be attempted with caution for the next few days. If you 
do upgrade your systems and find something that I have broken, please 
let me know as soon as possible.
-Nathan