Reorder tests to not use the same number (#2947)

Distinct numbers make re-running individual tests easier by helping with
tab-completion.

Completeness verified using:
% for i in $(seq 0 600)
do
  files=$(ls testcases/t/$(printf "%03d" $i)-*.t 2>&- | wc -l)
  [ "$files" != "0" ] && [ "$files" != "1" ] && echo "clash: $i"
done

testcases/t/289-ipc-shutdown-event.t

@@ -0,0 +1,71 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+#
+# Please read the following documents before working on tests:
+# • http://build.i3wm.org/docs/testsuite.html
+#   (or docs/testsuite)
+#
+# • http://build.i3wm.org/docs/lib-i3test.html
+#   (alternatively: perldoc ./testcases/lib/i3test.pm)
+#
+# • http://build.i3wm.org/docs/ipc.html
+#   (or docs/ipc)
+#
+# • http://onyxneon.com/books/modern_perl/modern_perl_a4.pdf
+#   (unless you are already familiar with Perl)
+#
+# Test the ipc shutdown event. This event is triggered when the connection to
+# the ipc is about to shutdown because of a user action such as with a
+# `restart` or `exit` command. The `change` field indicates why the ipc is
+# shutting down. It can be either "restart" or "exit".
+#
+# Ticket: #2318
+# Bug still in: 4.12-46-g2123888
+use i3test;
+
+SKIP: {
+    skip "AnyEvent::I3 too old (need >= 0.17)", 1 if $AnyEvent::I3::VERSION < 0.17;
+
+my $i3 = i3(get_socket_path());
+$i3->connect->recv;
+
+my $cv = AE::cv;
+my $timer = AE::timer 0.5, 0, sub { $cv->send(0); };
+
+$i3->subscribe({
+        shutdown => sub {
+            $cv->send(shift);
+        }
+    })->recv;
+
+cmd 'restart';
+
+my $e = $cv->recv;
+
+diag "Event:\n", Dumper($e);
+ok($e, 'the shutdown event should emit when the ipc is restarted by command');
+is($e->{change}, 'restart', 'the `change` field should tell the reason for the shutdown');
+
+# restarting kills the ipc client so we have to make a new one
+$i3 = i3(get_socket_path());
+$i3->connect->recv;
+
+$cv = AE::cv;
+$timer = AE::timer 0.5, 0, sub { $cv->send(0); };
+
+$i3->subscribe({
+        shutdown => sub {
+            $cv->send(shift);
+        }
+    })->recv;
+
+cmd 'exit';
+
+$e = $cv->recv;
+
+diag "Event:\n", Dumper($e);
+ok($e, 'the shutdown event should emit when the ipc is exited by command');
+is($e->{change}, 'exit', 'the `change` field should tell the reason for the shutdown');
+}
+
+done_testing;