Update for LLVM 3.2.
Try both version-suffixed and -unsuffixed variants of llvm-config when building the support library.
Cleanup main Rakefile.
Factor out LLVM#with_message_output.
Add bindings for LLVM linker.
Add vectorization passes.
Add LLVM::Type#dump.
Merge remote-tracking branch 'whitequark/dump-type'