User manual improvments
User manual improvments

- Document that you can use 'forall' in instance decls

- Change the sections a bit, so that big sections (like
  lexically scoped type variables, pattern synonyms,
  implicit parameters) become more visible

tjakway/ghcjvm,mcschroeder/ghc,shlevy/ghc,olsner/ghc,sgillespie/ghc,ezyang/ghc,tjakway/ghcjvm,vTurbine/ghc,ezyang/ghc,ezyang/ghc,oldmanmike/ghc,vTurbine/ghc,mettekou/ghc,mettekou/ghc,vikraman/ghc,ezyang/ghc,tjakway/ghcjvm,shlevy/ghc,sgillespie/ghc,mcschroeder/ghc,sdiehl/ghc,sdiehl/ghc,vikraman/ghc,tjakway/ghcjvm,mcschroeder/ghc,mettekou/ghc,snoyberg/ghc,sdiehl/ghc,vTurbine/ghc,vikraman/ghc,vikraman/ghc,olsner/ghc,tjakway/ghcjvm,mettekou/ghc,sgillespie/ghc,sdiehl/ghc,mettekou/ghc,sgillespie/ghc,sdiehl/ghc,olsner/ghc,vikraman/ghc,shlevy/ghc,olsner/ghc,oldmanmike/ghc,mcschroeder/ghc,shlevy/ghc,mettekou/ghc,vTurbine/ghc,ezyang/ghc,olsner/ghc,vikraman/ghc,snoyberg/ghc,oldmanmike/ghc,tjakway/ghcjvm,ezyang/ghc,mcschroeder/ghc,oldmanmike/ghc,tjakway/ghcjvm,snoyberg/ghc,vTurbine/ghc,vikraman/ghc,vTurbine/ghc,olsner/ghc,sgillespie/ghc,mcschroeder/ghc,oldmanmike/ghc,sdiehl/ghc,snoyberg/ghc,shlevy/ghc,snoyberg/ghc,sgillespie/ghc,ezyang/ghc,snoyberg/ghc,mcschroeder/ghc,shlevy/ghc,sgillespie/ghc,vTurbine/ghc,snoyberg/ghc,mettekou/ghc,sdiehl/ghc,shlevy/ghc,olsner/ghc,oldmanmike/ghc,oldmanmike/ghc