Merge remote-tracking branch 'origin/maint'

* origin/maint:
  bump to 2012 in skeletons.
  build: remove ancient Autoconf tests.
  doc: c++: complete the location documentation.
  c++: locations: provide convenience constructors.
  c++: locations: remove useless "inline".
  glr: do not use locations when they are not requested
  c++: use nullptr for C++11.
  build: simplify and improve the compiler warnings for tests.
  gnulib: update.
  maint: formatting changes.
  NEWS: update.
  Java: Fix syntax error handling without error token.
  tests: beware of -pedantic on large #line numbers.
  tests: when using the C++ compiler, use its flags too.

Conflicts:
	data/glr.c
	data/glr.cc
	data/lalr1.cc
	data/location.cc
	data/yacc.c
	tests/Makefile.am

data/lalr1.java

@@ -686,7 +686,7 @@ m4_popdef([b4_at_dollar])])dnl
               }
 
             /* Pop the current state because it cannot handle the error token.  */
-            if (yystack.height == 1)
+            if (yystack.height == 0)
               return false;
 
             ]b4_locations_if([yyerrloc = yystack.locationAt (0);])[