migrate to async IO model

new PIIODevice::interrupt() virtual method
new PIWaitEvent private class
PIEthernet and PISerial basically tested on Windows and Linux

libs/cloud/picloudserver.cpp

@@ -41,7 +41,7 @@ PICloudServer::PICloudServer(const PIString & path, PIIODevice::DeviceMode mode)
 
 
 PICloudServer::~PICloudServer() {
-	stop();
+	stopAndWait();
 	close();
 }
 
@@ -107,6 +107,11 @@ void PICloudServer::stopThreadedReadDevice() {
 }
 
 
+void PICloudServer::interrupt() {
+	eth.interrupt();
+}
+
+
 void PICloudServer::clientDisconnect(uint client_id) {
 	tcp.sendDisconnected(client_id);
 }
@@ -170,6 +175,11 @@ ssize_t PICloudServer::Client::writeDevice(const void * data, ssize_t size) {
 }
 
 
+void PICloudServer::Client::interrupt() {
+	cond_buff.notifyOne();
+}
+
+
 void PICloudServer::Client::pushBuffer(const PIByteArray & ba) {
 	if (!is_connected) return;
 	mutex_buff.lock();