Legacy: Drop deprecated APIs

Drop icsneoFindNeoDevices() and icsneoOpenNeoDevice() in favor of icsneoFindDevices() and icsneoOpenDevice(), respectively.

Also fixes:
- Failure to re-open a device after it has been closed with the C/legacy APIs
- NumberOfClients not being updated
- FIRE3 settings missing in icsneoGetDeviceSettingsType()

device/device.cpp

@@ -356,6 +356,10 @@ bool Device::close() {
 
 	stopHeartbeatThread = true;
 
+	if (isMessagePollingEnabled()) {
+		disableMessagePolling();
+	}
+	
 	if(isOnline())
 		goOffline();