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

tests/calc.at

@@ -241,7 +241,7 @@ int yylex (]AT_LEX_FORMALS[);
    are stored in a union, from which objects with constructors are
    excluded in C++). */
 %initial-action {
-  @$.initialize (0);
+  @$.initialize ();
 }
 ])])])[