Version 0.6 changes

At the time of writing, I'm experimenting with a new version based on mono-traversable. This will probably become version 0.6. As I'm experimenting with things, I'll try to keep notes on notable changes.

• Far fewer type classes.
• map is now just fmap and won't work for monomorphic containers or Sets.
  • For monomorphic containers, use omap.
  • For sets, unboxed vectors, and storable vectors, use looseMap.
• For Maps, you must use mapFromList and mapToList. Similar for Sets: setFromList and setToList.
• insert, delete, singleton are now insertMap/deleteMap/singletonMap or insertSet/deleteSet/singletonSet.
• singleton works for sequences (ByteString, Vector, etc)
• No more empty, just use mempty.
• Less built-in FilePath support. Use fp(From/To)(String/Text)
• elem/notElem works for sequences, member/notMember works for containers (Map/Set)
• fold becomes foldl'
• show is now monomorphic (produces a String), you should use tshow if you want Text.
• ClassyPrelude.Conduit has a bunch of chunked functions.
• <> is now imported from Semigroup. If you want Monoidal appending instead (e.g., you're using a datatype without a Semigroup instance), use ++.

Notice the pattern: there are a number of places where you need to be much more explicit about which function you're going to use (mapFromList vs. pack/fromList). Overall, I think it's actually a nice change, as code becomes more readable.