This is the second batch of makefile changes. Libg++ makefiles were

This is the second batch of makefile changes.  Libg++ makefiles were
checked in earlier.  These are Makefiles relevant to the progressive
release currently in progress.

* added exec_prefix
* default bindir now exec_prefix/bin
* default libdir now exec_prefix/lib
* default mandir now prefix/man
* default infodir now prefix/info
* added oldincludedir, default NULL
* remove all traces of the old -subdirs and -namesubdir support,
  including code, for loops, and all subdir/unsubdir stuff.
* remove old style staging targets {de-}stage[1234], comparison,
  bootstrapN, from all but the bootstrappable tools.
* added check targets.
* removed any "Last Mod" lines.
* forced copyrights to '92 and shifted some from Cygnus to FSF.
* added tooldir and program_prefix where needed.
* updated texinfo and man pages, removed all references to multiple
  hosts or targets.