Move components into dedicated subdirectory

This brings us a lot more tidiness.

components/datetime.c

@@ -0,0 +1,16 @@
+/* See LICENSE file for copyright and license details. */
+#include <time.h>
+
+#include "../util.h"
+
+const char *
+datetime(const char *fmt)
+{
+	time_t t;
+
+	t = time(NULL);
+	if (strftime(buf, sizeof(buf), fmt, localtime(&t)) == 0)
+		return NULL;
+
+	return buf;
+}