minor cleanups to configure.ac to reduce autoconf-2.70 warnings a bit.

configure output is practically unchanged. there are still lots of
AC_TRY_COMPILE/AC_TRY_LINK replacements needed to really eliminate
the warnings, but that's for another time.

test/configure

@@ -1919,6 +1919,7 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 
 
+
 ac_aux_dir=
 for ac_dir in $srcdir/../build-scripts; do
   if test -f "$ac_dir/install-sh"; then
@@ -2020,7 +2021,6 @@ case $host_os in *\ *) host_os=`echo "$host_os" | sed 's/ /-/g'`;; esac
 
 
 
-
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -2812,7 +2812,6 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 
 
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for an ANSI C-conforming const" >&5
 $as_echo_n "checking for an ANSI C-conforming const... " >&6; }
 if ${ac_cv_c_const+:} false; then :

test/configure.ac

@@ -1,16 +1,15 @@
 dnl Process this file with autoconf to produce a configure script.
-AC_INIT(README)
+AC_INIT
+AC_CONFIG_SRCDIR([README])
 
 dnl Detect the canonical build and host environments
 AC_CONFIG_AUX_DIRS($srcdir/../build-scripts)
 AC_CANONICAL_HOST
 
 dnl Check for tools
-
 AC_PROG_CC
 
 dnl Check for compiler environment
-
 AC_C_CONST
 
 dnl We only care about this for building testnative at the moment, so these
@@ -42,7 +41,7 @@ case "$host" in
     *-*-aix*)
         ISUNIX="true"
         EXE=""
-        if test x$ac_cv_prog_gcc = xyes; then
+        if test x$ac_cv_c_compiler_gnu = xyes; then
             CFLAGS="-mthreads"
         fi
         SYS_GL_LIBS=""
@@ -201,4 +200,5 @@ fi
 AC_SUBST(SDL_TTF_LIB)
 
 dnl Finally create all the generated files
-AC_OUTPUT([Makefile])
+AC_CONFIG_FILES([Makefile])
+AC_OUTPUT