migrate to async IO model

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

libs/main/io_devices/piiodevice.cpp

@@ -131,8 +131,8 @@ PIIODevice::PIIODevice(const PIString & path, PIIODevice::DeviceMode mode): PIOb
 
 
 PIIODevice::~PIIODevice() {
-	stop();
-	waitThreadedReadFinished();
+	destroying = true;
+	stopAndWait();
 }
 
 
@@ -215,8 +215,10 @@ void PIIODevice::stopThreadedRead() {
 	read_thread.stop();
 #else
 	read_thread.stop();
-	read_thread.interrupt();
-	stopThreadedReadDevice();
+	if (!destroying) {
+		interrupt();
+		stopThreadedReadDevice();
+	}
 	if (reading_now) {
 		read_thread.terminate();
 		reading_now = false;
@@ -271,6 +273,13 @@ void PIIODevice::stop() {
 }
 
 
+void PIIODevice::stopAndWait(int timeout_ms) {
+	stop();
+	waitThreadedReadFinished(timeout_ms);
+	waitThreadedWriteFinished(timeout_ms);
+}
+
+
 ssize_t PIIODevice::read(void * read_to, ssize_t max_size) {
 	ssize_t ret = readDevice(read_to, max_size);
 	return ret;