.gitignore: Add stuff
InferMonad unrolled towards not really being a writer monad (combining writer states may throw error)

This doesn't affect performance much.
Carry Constraints in Infer's pseudo-Writer.

Constraints not yet used.
Constraints told from record inference. Missing propagation through Schemes.
Lamdu.Infer.{Scheme,Constraints,TypeVars} -> Lamdu.Infer.Internal.*. Re-export the types
Scheme: Make record
Add failing test
Less applySubst in let
Schemes carry constraints
Left-associative Writer monad, large performance improvement
typeInference returns a Scheme
Use foldl' and not foldr for deleteKeySet
Add unification for non-flattened records when applicable. Performance benefit on small inference, degradation on large inference
Fix style
Oops: Fix two bugs in record variable constraints