Update to pacify recent GCC's static checking.

These changes pacify gcc 4.8.2-19ubuntu1 on Ubuntu 14.04,
and take advantage of recently-added GCC options when compiling
with GCC_DEBUG_FLAGS.
* Makefile (GCC_DEBUG_FLAGS): Add -Wdeclaration-after-statement,
-Wjump-misses-init, -Wsuggest-attribute=format.
* date.c (copyright, sccsid):
* strftime.c (sccsid):
Remove unused vars.
* date.c (main):
* localtime.c (tzparse):
Remove no-longer-needed uses of INITIALIZE; GCC is smart enough to
figure these out on its own now.
* localtime.c (gmtsub): Redo initialization of gmt_is_set to pacify GCC.
Retry malloc next time even if it failed this time.
* private.h, zdump.c (GNUC_or_lint): Remove, as it provoked a GCC
diagnostic about unused macros in some cases.  Instead, just use
'lint'.  All uses removed.
(TZ_DOMAIN): Don't define unless needed, as otherwise it provokes
a GCC diagnostic about unused macros.
* private.h (INITIALIZE): Simplify accordingly.
* NEWS: Document this.

private.h

@@ -352,25 +352,11 @@ static time_t const time_t_max =
 ** INITIALIZE(x)
 */
 
-#ifndef GNUC_or_lint
 #ifdef lint
-#define GNUC_or_lint
-#endif /* defined lint */
-#ifndef lint
-#ifdef __GNUC__
-#define GNUC_or_lint
-#endif /* defined __GNUC__ */
-#endif /* !defined lint */
-#endif /* !defined GNUC_or_lint */
-
-#ifndef INITIALIZE
-#ifdef GNUC_or_lint
-#define INITIALIZE(x)	((x) = 0)
-#endif /* defined GNUC_or_lint */
-#ifndef GNUC_or_lint
-#define INITIALIZE(x)
-#endif /* !defined GNUC_or_lint */
-#endif /* !defined INITIALIZE */
+# define INITIALIZE(x)	((x) = 0)
+#else
+# define INITIALIZE(x)
+#endif
 
 /*
 ** For the benefit of GNU folk...
@@ -386,9 +372,9 @@ static time_t const time_t_max =
 #endif /* !HAVE_GETTEXT */
 #endif /* !defined _ */
 
-#ifndef TZ_DOMAIN
-#define TZ_DOMAIN "tz"
-#endif /* !defined TZ_DOMAIN */
+#if !defined TZ_DOMAIN && defined TZ_DOMAINDIR
+# define TZ_DOMAIN "tz"
+#endif
 
 #if HAVE_INCOMPATIBLE_CTIME_R
 #undef asctime_r