Deprecate Data.Aeson.Generic

[basvandijk]

I've been thinking about the idea of deprecating the Data.Aeson.Generic module in favor of the GHC Generics and TH encoders because of the following reasons:

• It has issues: Data.Aeson.Generic.decode unable to parse Data.Aeson.Generic.encode output (aeson-0.6.0.0) #75, Make Data.Aeson.Generic encode Maybe the same way as Data.Aeson.Encode #84, Incorrect fromJSON parsing of Nothing-values in Generic module  #101, incorrect "fromJSON" parsing of Data.Set.Set #107.
• It's slow compared to GHC Generics and very, very, very slow compared to TH. See some recent benchmark results in Parameterize generic encoding with options #116.
• The encoding/decoding can't currently be configured using the encoding Options.
• Related to the previous point: GHC Generics and TH use compatible encoders/decoders (if the same Options have been used). Data.Aeson.Generic does things slightly differently.
• The original author is not around to work on it. Who wrote it anyway?

I would be interested in your opinion on this.

[bos]

I think that's a great idea.

[basvandijk]

Done: 12ed274