Test & fix langset comparisons.
 
Add docstrings everywhere!
 
Improve handling of invalid FontConfig data.
 
Fuzz test roundtrip conversions between C & Haskell datastructures!
 
Properly handle ambiguity in empty char/lang sets.
 
fuzz-test MessagePack implementations.
 
Implement utils for loading queried fonts.
 
Integrate fontsets with Haskell Stylist.
 
Implement Stylist traits for FontConfig patterns!
 
Improve memory safety & error checks.
 
Expose font weight adjustments & correct current-config refcount.
 
Write init/finalize & pattern language bindings, haskell-side!
 
Encode & decode charsets on C side (fix Haskell side)
 
Datamodel FontConfig in Haskell.