Remove support for Hugs and NHC98.

Cabal/Cabal.cabal

Cabal/Distribution/Compat/TempFile.hs

Cabal/Distribution/InstalledPackageInfo.hs

Cabal/Distribution/PackageDescription/Parse.hs

Cabal/Distribution/Simple/Build.hs

Cabal/Distribution/Simple/Build/PathsModule.hs

Cabal/Distribution/Simple/BuildPaths.hs

Cabal/Distribution/Simple/Configure.hs

Cabal/Distribution/Simple/GHC/IPI641.hs

Cabal/Distribution/Simple/GHC/IPI642.hs

Cabal/Distribution/Simple/Hugs.hs

Cabal/Distribution/Simple/Install.hs

Cabal/Distribution/Simple/InstallDirs.hs

Cabal/Distribution/Simple/LocalBuildInfo.hs

Cabal/Distribution/Simple/NHC.hs

Cabal/Distribution/Simple/PreProcess.hs

Cabal/Distribution/Simple/Program.hs

Cabal/Distribution/Simple/Program/Builtin.hs

Cabal/Distribution/Simple/Register.hs

Cabal/Distribution/Simple/Setup.hs