Disable DatatypeContexts by default
Disable DatatypeContexts by default

The Haskell' committee decided to remove datatype contexts from the language:
http://www.haskell.org/pipermail/haskell-prime/2011-January/003335.html

shlevy/ghc,anton-dessiatov/ghc,christiaanb/ghc,tjakway/ghcjvm,nkaretnikov/ghc,mcmaniac/ghc,vTurbine/ghc,AlexanderPankiv/ghc,wxwxwwxxx/ghc,christiaanb/ghc,nomeata/ghc,elieux/ghc,fmthoma/ghc,vikraman/ghc,mfine/ghc,bitemyapp/ghc,urbanslug/ghc,ekmett/ghc,gcampax/ghc,hferreiro/replay,acowley/ghc,AlexanderPankiv/ghc,vTurbine/ghc,green-haskell/ghc,siddhanathan/ghc,tibbe/ghc,sdiehl/ghc,nathyong/microghc-ghc,anton-dessiatov/ghc,acowley/ghc,ryantm/ghc,AlexanderPankiv/ghc,olsner/ghc,gridaphobe/ghc,mcmaniac/ghc,elieux/ghc,ryantm/ghc,bitemyapp/ghc,ryantm/ghc,wxwxwwxxx/ghc,bitemyapp/ghc,siddhanathan/ghc,GaloisInc/halvm-ghc,hferreiro/replay,sdiehl/ghc,sgillespie/ghc,mettekou/ghc,spacekitteh/smcghc,ekmett/ghc,forked-upstream-packages-for-ghcjs/ghc,olsner/ghc,sdiehl/ghc,TomMD/ghc,green-haskell/ghc,wxwxwwxxx/ghc,frantisekfarka/ghc-dsi,nkaretnikov/ghc,mettekou/ghc,ilyasergey/GHC-XAppFix,mfine/ghc,tjakway/ghcjvm,hferreiro/replay,nathyong/microghc-ghc,oldmanmike/ghc,holzensp/ghc,ml9951/ghc,lukexi/ghc-7.8-arm64,sgillespie/ghc,oldmanmike/ghc,green-haskell/ghc,ryantm/ghc,mcmaniac/ghc,sdiehl/ghc,siddhanathan/ghc,hferreiro/replay,ilyasergey/GHC-XAppFix,mettekou/ghc,anton-dessiatov/ghc,ekmett/ghc,jstolarek/ghc,frantisekfarka/ghc-dsi,ezyang/ghc,acowley/ghc,lukexi/ghc-7.8-arm64,vTurbine/ghc,da-x/ghc,tjakway/ghcjvm,da-x/ghc,da-x/ghc,mettekou/ghc,mfine/ghc,vTurbine/ghc,gcampax/ghc,da-x/ghc,anton-dessiatov/ghc,nushio3/ghc,oldmanmike/ghc,vikraman/ghc,vikraman/ghc,nushio3/ghc,hferreiro/replay,frantisekfarka/ghc-dsi,mcmaniac/ghc,christiaanb/ghc,mettekou/ghc,GaloisInc/halvm-ghc,acowley/ghc,siddhanathan/ghc,mcmaniac/ghc,fmthoma/ghc,elieux/ghc,gcampax/ghc,lukexi/ghc,lukexi/ghc-7.8-arm64,snoyberg/ghc,GaloisInc/halvm-ghc,ghc-android/ghc,TomMD/ghc,TomMD/ghc,mfine/ghc,vikraman/ghc,hferreiro/replay,gridaphobe/ghc,holzensp/ghc,sgillespie/ghc,tibbe/ghc,spacekitteh/smcghc,gridaphobe/ghc,lukexi/ghc,fmthoma/ghc,shlevy/ghc,urbanslug/ghc,urbanslug/ghc,green-haskell/ghc,frantisekfarka/ghc-dsi,ml9951/ghc,oldmanmike/ghc,sgillespie/ghc,mcschroeder/ghc,gcampax/ghc,nushio3/ghc,nomeata/ghc,tjakway/ghcjvm,mfine/ghc,olsner/ghc,mcschroeder/ghc,acowley/ghc,urbanslug/ghc,vikraman/ghc,tjakway/ghcjvm,wxwxwwxxx/ghc,elieux/ghc,forked-upstream-packages-for-ghcjs/ghc,nathyong/microghc-ghc,ekmett/ghc,bitemyapp/ghc,nushio3/ghc,ghc-android/ghc,ilyasergey/GHC-XAppFix,elieux/ghc,sgillespie/ghc,green-haskell/ghc,gridaphobe/ghc,mcschroeder/ghc,elieux/ghc,siddhanathan/ghc,frantisekfarka/ghc-dsi,urbanslug/ghc,snoyberg/ghc,nathyong/microghc-ghc,sdiehl/ghc,snoyberg/ghc,ml9951/ghc,sdiehl/ghc,anton-dessiatov/ghc,AlexanderPankiv/ghc,lukexi/ghc,gcampax/ghc,ezyang/ghc,christiaanb/ghc,forked-upstream-packages-for-ghcjs/ghc,AlexanderPankiv/ghc,forked-upstream-packages-for-ghcjs/ghc,GaloisInc/halvm-ghc,ghc-android/ghc,mettekou/ghc,wxwxwwxxx/ghc,urbanslug/ghc,fmthoma/ghc,nushio3/ghc,fmthoma/ghc,christiaanb/ghc,ezyang/ghc,tibbe/ghc,tjakway/ghcjvm,gcampax/ghc,snoyberg/ghc,nomeata/ghc,AlexanderPankiv/ghc,TomMD/ghc,olsner/ghc,spacekitteh/smcghc,ryantm/ghc,GaloisInc/halvm-ghc,nathyong/microghc-ghc,sgillespie/ghc,TomMD/ghc,lukexi/ghc-7.8-arm64,tjakway/ghcjvm,wxwxwwxxx/ghc,forked-upstream-packages-for-ghcjs/ghc,mcschroeder/ghc,shlevy/ghc,spacekitteh/smcghc,nomeata/ghc,snoyberg/ghc,nomeata/ghc,GaloisInc/halvm-ghc,fmthoma/ghc,da-x/ghc,AlexanderPankiv/ghc,spacekitteh/smcghc,nushio3/ghc,urbanslug/ghc,ml9951/ghc,ghc-android/ghc,mcschroeder/ghc,jstolarek/ghc,acowley/ghc,olsner/ghc,christiaanb/ghc,mettekou/ghc,mfine/ghc,oldmanmike/ghc,nkaretnikov/ghc,olsner/ghc,jstolarek/ghc,da-x/ghc,nathyong/microghc-ghc,ezyang/ghc,nkaretnikov/ghc,oldmanmike/ghc,ml9951/ghc,sgillespie/ghc,ekmett/ghc,siddhanathan/ghc,ezyang/ghc,acowley/ghc,forked-upstream-packages-for-ghcjs/ghc,nathyong/microghc-ghc,jstolarek/ghc,nkaretnikov/ghc,gridaphobe/ghc,siddhanathan/ghc,mcschroeder/ghc,anton-dessiatov/ghc,ml9951/ghc,lukexi/ghc,fmthoma/ghc,lukexi/ghc,gcampax/ghc,mfine/ghc,sdiehl/ghc,shlevy/ghc,holzensp/ghc,vikraman/ghc,jstolarek/ghc,wxwxwwxxx/ghc,shlevy/ghc,ilyasergey/GHC-XAppFix,ezyang/ghc,snoyberg/ghc,forked-upstream-packages-for-ghcjs/ghc,da-x/ghc,nkaretnikov/ghc,holzensp/ghc,ml9951/ghc,vikraman/ghc,GaloisInc/halvm-ghc,shlevy/ghc,oldmanmike/ghc,hferreiro/replay,shlevy/ghc,holzensp/ghc,tibbe/ghc,nkaretnikov/ghc,lukexi/ghc-7.8-arm64,vTurbine/ghc,gridaphobe/ghc,ghc-android/ghc,vTurbine/ghc,snoyberg/ghc,olsner/ghc,elieux/ghc,vTurbine/ghc,christiaanb/ghc,nushio3/ghc,TomMD/ghc,tibbe/ghc,TomMD/ghc,gridaphobe/ghc,ghc-android/ghc,bitemyapp/ghc,ml9951/ghc,mcschroeder/ghc,ezyang/ghc,ghc-android/ghc,anton-dessiatov/ghc