gnulib-tool --import: more advice

[Bruno Haible]

To make gnulib-tool a little more developer-friendly:

        * gnulib-tool (func_import): Emit more comments into gnulib.m4.
        Emit more advice.

*** gnulib-tool.bak     2005-08-29 00:16:05.000000000 +0200
--- gnulib-tool 2005-08-29 00:10:56.000000000 +0200
***************
*** 836,839 ****
--- 836,842 ----
      echo "# Reproduce by: $actioncmd"
      echo
+     echo "# This macro should be invoked from $configure_ac, in the section"
+     echo "# \"Checks for programs\", right after AC_PROG_CC, and certainly 
before"
+     echo "# any checks for libraries, header files, types and library 
functions."
      echo "AC_DEFUN([gl_EARLY],"
      echo "["
***************
*** 846,850 ****
--- 849,855 ----
      echo "])"
      echo
+     echo "# This macro should be invoked from $configure_ac, in the section"
+     echo "# \"Check for header files, types and library functions\"."
      echo "AC_DEFUN([gl_INIT],"
      echo "["
      for module in $modules; do
***************
*** 890,896 ****
    done | LC_ALL=C sort -u | sed -e '/^$/d;' -e 's/^/  /'
    echo
!   echo "Don't forget to add \"$sourcebase/Makefile\""
!   echo "to AC_CONFIG_FILES in \"$configure_ac\" and to mention"
!   echo "\"`basename $sourcebase`\" in SUBDIRS in some Makefile.am."
  }
  
--- 909,920 ----
    done | LC_ALL=C sort -u | sed -e '/^$/d;' -e 's/^/  /'
    echo
!   echo "Don't forget to"
!   echo "  - add \"$sourcebase/Makefile\" to AC_CONFIG_FILES in $configure_ac,"
!   sourcebase_dir=`echo "$sourcebase" | sed -n -e 's,/[^/]*$,/,p'`
!   sourcebase_base=`basename "$sourcebase"`
!   echo "  - mention \"${sourcebase_base}\" in SUBDIRS in 
${sourcebase_dir}Makefile.am,"
!   echo "  - mention \"-I ${m4base}\" in ACLOCAL_AMFLAGS in Makefile.am,"
!   echo "  - invoke gl_EARLY in $configure_ac, right after AC_PROG_CC,"
!   echo "  - invoke gl_INIT in $configure_ac."
  }