Merge branch 'maint'

* maint:
  maint: don't use "union" merge driver for NEWS anymore
  build: avoid too greedy rebuilds in the testsuite
  tests: avoid yet another spurious environment influence
  tests: fix a failure in Lex/C++ tests on Mac OS X
  tests: fix a spurious failure due to truncated timestamps
  build: require autoconf 2.69
  build: don't require minimal automake version in AM_INIT_AUTOMAKE

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

diff --cc configure.ac
index 1885836,22a158f..3f55df7
--- 1/configure.ac
--- 2/configure.ac
+++ b/configure.ac
@@@ -15,8 -15,8 +15,8 @@@
  # You should have received a copy of the GNU General Public License
  # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  
- AC_PREREQ([2.68])
+ AC_PREREQ([2.69])
 -AC_INIT([GNU Automake], [1.12.0a], [bug-automake@gnu.org])
 +AC_INIT([GNU Automake], [1.12a], [bug-automake@gnu.org])
  
  AC_CONFIG_SRCDIR([automake.in])
  AC_CONFIG_AUX_DIR([lib])