Updates for Automake 1.13.

autoreconf will install config/test-driver, ignore it.
Update gettext m4 and po files to version 0.18.2.
Use AM_CPPFLAGS instead of INCLUDES.
All changes are backward compatible with Automake 1.11.
diff --git a/.gitignore b/.gitignore
index 6cfcc7c..d463556 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,6 +30,7 @@
 config/depcomp
 config/install-sh
 config/missing
+config/test-driver
 config/ylwrap
 configure
 elfutils.spec