autoconf: portability fixes

The rework of the host tools discovery caused autoconf to embed
absolute paths to staging_dir/host/bin/perl into the shebang
of the generated autoconfig executables.

Switch to the portable "/usr/bin/env perl" and enable global
warnings through "$^W" instead of the "-w" interpreter argument.

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

SVN-Revision: 44971

tools/autoconf/patches/001-no_emacs_lib.patch

@@ -1,6 +1,6 @@
 --- a/lib/Makefile.am
 +++ b/lib/Makefile.am
-@@ -16,7 +16,7 @@
+@@ -15,7 +15,7 @@
  # You should have received a copy of the GNU General Public License
  # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  
@@ -11,7 +11,7 @@
  
 --- a/lib/Makefile.in
 +++ b/lib/Makefile.in
-@@ -226,7 +226,7 @@ target_alias = @target_alias@
+@@ -225,7 +225,7 @@ target_alias = @target_alias@
  top_build_prefix = @top_build_prefix@
  top_builddir = @top_builddir@
  top_srcdir = @top_srcdir@