Added example for non blocking polling

examples/epoll.js

@@ -0,0 +1,48 @@
+const { SRT } = require('../index.js');
+
+const srt = new SRT();
+const socket = srt.createSocket();
+if (socket !== -1) {
+  console.log("Created socket: " + socket);
+} 
+
+let result;
+
+result = srt.bind(socket, "0.0.0.0", 1234);
+if (!result) {
+  console.log("Bind success");
+} else {
+  console.log(result);
+}
+
+result = srt.listen(socket, 10);
+if (!result) {
+  console.log("Listen success");
+} else {
+  console.log(result);
+}
+
+const epid = srt.epollCreate();
+srt.epollAddUsock(epid, socket, SRT.EPOLL_IN | SRT.EPOLL_ERR);
+
+console.log("Waiting for action");
+
+while (true) {
+  const events = srt.epollUWait(epid, 500);
+  events.forEach(event => {
+    const status = srt.getSockState(event.socket);
+    if (status === SRT.SRTS_BROKEN || status === SRT.SRTS_NONEXIST || status === SRT.SRTS_CLOSED) {
+      console.log("Client disconnected");
+      srt.close(event.socket);
+    } else if (event.socket === socket) {
+      const fhandle = srt.accept(socket);
+      console.log("New connection");
+      srt.epollAddUsock(epid, fhandle, SRT.EPOLL_IN | SRT.EPOLL_ERR);
+    } else {
+      while (true) {
+        const chunk = srt.read(event.socket, 1316);
+        console.log("Read chunk: " + chunk.length);      
+      }
+    }
+  });
+}