dtrace: honor LC_NUMERIC for %'d and alike, and LC_TIME for %T

Note that the public documentation on dtrace.org fails to mention %T and
incorrectly documents %Y.  The latter actually uses format "%Y %b %e %T"
where %b is always in C locale.

Discussed with:	markj
MFC after:	1 month
Sponsored by:	Panzura

cddl/contrib/opensolaris/cmd/dtrace/dtrace.c

@@ -51,6 +51,7 @@
 #include <libproc.h>
 #endif
 #ifdef __FreeBSD__
+#include <locale.h>
 #include <spawn.h>
 #endif
 
@@ -1316,6 +1317,14 @@ main(int argc, char *argv[])
 	struct ps_prochandle *P;
 	pid_t pid;
 
+#ifdef __FreeBSD__
+	/* For %'d and the like. */
+	(void) setlocale(LC_NUMERIC, "");
+
+	/* For %T. */
+	(void) setlocale(LC_TIME, "");
+#endif
+
 	g_pname = basename(argv[0]);
 
 	if (argc == 1)