Add test for issue #1429.

UDP receive timeout doesn't work for the libevent driver.

(cherry picked from commit 443e071)

tests/vibe.core.net.1429/dub.sdl

@@ -0,0 +1,4 @@
+name "tests"
+description "TCP disconnect task issue"
+dependency "vibe-d:core" path="../../"
+versions "VibeDefaultMain"

tests/vibe.core.net.1429/source/app.d

@@ -0,0 +1,29 @@
+import vibe.core.core;
+import vibe.core.log : logInfo;
+import vibe.core.net;
+import core.time : msecs;
+import std.datetime : Clock, UTC;
+
+shared static this()
+{
+	auto udp = listenUDP(11429, "127.0.0.1");
+
+	runTask({
+		sleep(500.msecs);
+		assert(false, "Receive call did not return in a timely manner. Killing process.");
+	});
+
+	runTask({
+		auto start = Clock.currTime(UTC());
+		try {
+			udp.recv(100.msecs);
+			assert(false, "Timeout did not occur.");
+		} catch (Exception e) {
+			auto duration = Clock.currTime(UTC()) - start;
+			assert(duration >= 99.msecs, "Timeout occurred too early");
+			assert(duration >= 99.msecs && duration < 150.msecs, "Timeout occurred too late.");
+			logInfo("UDP receive timeout test was successful.");
+			exitEventLoop();
+		}
+	});
+}