F77 additions from Matthew D Langston * m4/f77.m4: New file. * m4/Makefile.am (m4data_DATA): Added f77.m4. * automake.in (resolve_linker): Put the Fortran 77 linker where it needs to be. * automake.in (lang_f77_finish): Add support for Fortran 77. * automake.in (f77_extensions): New helper function for function `lang_f77_finish'. * automake.in (lang_f77_rewrite): Change to return success. * automake.in (scan_one_configure_file): Add test for the Fortran 77 compiler. * automake.in (finish_languages): Changed tests for "C++ only" to "C++ and/or Fortran 77 only", and renamed `all_cxx' to `non_c'. * automake.in: Registered the ppf77 language (`.F' extension) for preprocessed Fortran 77. * automake.in: Registered the ratfor language (`.r' extension). * automake.in: Registered Fortran 77 header files with the "header language" (`.inc' extension). * automake.texi: Added several new index entries. * automake.texi: - Add `@ovindex' (output variable index). - Merge `@defmac' (Autoconf macros) and `@ovindex' to the General Index. * automake.texi (Macros): - Changed the `@table @code' list of macros to `@defmac'. - Add `AC_PROG_FC' and `MDL_F77_LIBRARY_LDFLAGS' to the list. * automake.texi (C++): Change `@table' to `@vtable'. * automake.texi (Fortran 77): Add Fortran 77 documentation.