All installed Haskell prgms have an inplace and an installed version

All installed Haskell prgms have an inplace and an installed version
- GHC installs a range of compiled Haskell programs in addition to the actual
  compiler.  To ensure that they all run on the platform targeted by the build
  (which may have different libraries installed than the build host), we need
  to make sure that all compiled Haskell code going into an install is build
  with the stage 1 compiler, not the bootstrap compiler.  Getting this right
  is especially important on the Mac to enable builds that work on Mac OS X
  versions that are older than the one performing the build.
- For all installed utils implemented in Haskell (i.e., ghc-pkg, hasktags,
  hsc2hs, runghc, hpc, and pwd) we compile two versions, an inplace version
  and a version for installation.  The former is build by the bootstrap
  compiler during the stage 1 build and the latter is build by the stage 1
  compiler during the stage 2 build.
- This is really very much as the setup for ghc itself, only that we don't use
  separate stage1/ and stage2/ build directories.  Instead, we clean before
  each build.  CAVEAT: This only works properly if invoked from the
  toplevel Makefile.
- Instead of UseStage1=YES (as used by the previous binary-dist-specific
  recompilation), we now use the same $(stage) variables as used for the
  compiler proper - to increase uniformity and to avoid extra conditionals for
  the install target.