Fix reading of older Cabal `setup-config`s
Make getSystemLibDir use `GHC.Paths` instead of running `ghc`
Fix tests for Cabal <= 1.16
Print useful information when running spec
Fix warnings
Fix Cabal >= 1.18
Merge pull request #249 from DanielG/dev-cabal1.16

Fix reading setup-config with Cabal <= 1.16