[Interest] How to build Qt using multiple CPU's on Mac?

[Tony Rietwyk]

Hi Everybody, 

On windows when I run nmake after configure, it uses all of my CPU's and is
finished in under 2 hours.  

On mac OSX Lion with XCode 4.3.2, when I run make after configure, it only
uses 1 CPU.   My google fu is not working and I can't find the parameter for
make to get it to use more CPU's.  

(It seems the problems forcing Qt compile to target OSX 10.6 have come back
in 4.8.3, hence my need to build Qt a few times already).  

Thanks! 

Tony.