Add script that prints the uptime after waiting for all servers.

It waits for the message port of each application to become available
using waitfor and then waits for the application to actually reply
using hey. This establishes the criterion of the boot process being
complete as "all servers (and Tracker & Deskbar) are started and
respond to messages".

src/tests/misc/boot_time_logger.sh

@@ -0,0 +1,34 @@
+#!/bin/sh
+
+
+# Send a message to and wait for a reply from all servers to determine when
+# everything's ready.
+SIGNATURES="
+	application/x-vnd.haiku-registrar
+	application/x-vnd.Haiku-mount_server
+	application/x-vnd.Haiku-powermanagement
+	application/x-vnd.Haiku-cddb_daemon
+	application/x-vnd.Haiku-midi_server
+	application/x-vnd.haiku-net_server
+	application/x-vnd.Haiku-debug_server
+	application/x-vnd.Be-PSRV
+	application/x-vnd.haiku-package_daemon
+	application/x-vnd.Haiku-notification_server
+	application/x-vnd.Be-input_server
+	application/x-vnd.Be.media-server
+	application/x-vnd.Be.addon-host
+	application/x-vnd.Be-TRAK
+	application/x-vnd.Be-TSKB"
+
+for SIGNATURE in $SIGNATURES
+do
+	waitfor -m $SIGNATURE
+	hey -s $SIGNATURE get
+	if [ $? -ne 0 ]
+	then
+		echo "Failed to get a reply for $SIGNATURE"
+		exit 1
+	fi
+done
+
+system_time