Revision to reflect new role annotation syntax in GHC.
Add test helper
Fixes #231
Fixes #256

We inject -dynamic-too into flags before we run all our actions in the
GHC monad.
Add new field to DynFlags
Fallback to ./resources when Cabal data is not found

(so that themes are found during development)
Fixes #5
Print missing documentation. Fixes #258.