See this in action here: http://api.three20.info/
All precompiled headers now use the Xcode 3.2.4 fix if necessary to resolve errors when compiling with LLVM 1.5. If you would like to build Three20 with LLVM 1.5, simply edit src/common/Configurations/Library.xcconfig and uncomment the necessary lines. The next change will resolve warnings associated with building Three20 with LLVM 1.5.
Network depends upon the Core library, so we should have access to the Core library when we import only the Network header.
Let's just use the basic name for the default libs. If someone is running Xcode 3.2.5 or 3.2.2, they can choose to build those projects instead.