OSX 32/64 bits support for JDK7 patch for review

[Henri Gomez]

> First, let me say this is greatly appreciated. I would also say 'it looks
> good, go for it' but we are going to need to coordinate this with our
> release engineering team.

I saw and commented a potential issue yesterday (basic Tomcat/Jenkins
running in -d32 -server and core dumped).
Switching same application under -d32 -client fixed problem, unsure if
it's a bug or not.

> This change turns on the universal build by default. Does it still allow the
> ability to compile 64-bit only, with either a -D flag or other external
> switch?

Default is universal build with this patch but we could switch back to
64bits default.
In this case, providing ARCH=universal to make will activate universal mode