[Bro] Build Fail on OS X Lion

[Siwek, Jonathan Luke]

> 
> Here's the build log snippet after adding the code you suggested:

The errors look even funkier now -- when you added code to net_flow.pac, was it just the two new lines in the %extern block or did you add a whole other block?  I meant the former (a single %extern block that looks like what I showed).

Also, can you send your build/CMakeCache.txt so I can check the environment?

+Jon