dnl AC_WITHNONE_IF(flag,cond) - not unlike AM_CONDITIONAL
AC_DEFUN(AC_WITHNONE_IF,
[AC_SUBST($1_WITH)
AC_SUBST($1_NONE)
if $2; then 
    $1_WITH=""
    $1_NONE="#"
else 
    $1_WITH="#"
    $1_NONE=""
fi
])

dnl AC_WITHOUT_SUBST(varname) - not unlike AM_CONDITIONAL
AC_DEFUN(AC_SUBST_WITHOUT,
[AC_SUBST(WITH_$1)
AC_SUBST(WITHOUT_$1)
v=`echo [$]$1`
a="yes"
if test "_$v" = "_" ; then v="no" ; fi
if test "_$v" = ":" ; then v="no" ; fi
if test "_$v" = "_0" ; then v="no" ; fi
if test "_$v" = "_no" ; then v="no" ; fi
if test "_$v" = "_false" ; then v="no" ; fi
if test "$a" = "yes" ; then 
    WITH_$1=""
    WITHOUT_$1="#"
else 
    WITH_$1="#"
    WITHOUT_$1=""
fi
])