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.
Compatibility with OverloadedRecordFields changes
Create correct anchors for record selector bindings
Support syntactic sugar
Don't link to overloaded record fields
Print field label rather than selector in Hoogle backend
Add map from selector names to field labels, so LaTeX backend can print them correctly
Initialise missing field with placeholder
Include selectors in exported names
Export FieldMap via InstalledInterface to fix selector names in index

This requires a bump of the interface file version, but I'm not sure how to do
that, or even if this is the right solution.
Use FastString field labels