DevMgr: Add DeviceReattacher daemon plumbing

This is the plumbing for a periodic polling thread that tries
to reattach DA specs that failed to attach in the startup phase.

smocore/include/deviceManager/deviceReattacher.h

@@ -0,0 +1,44 @@
+#ifndef DEVICEREATTACHER_H
+#define DEVICEREATTACHER_H
+
+#include <atomic>
+#include <memory>
+#include <boost/asio.hpp>
+
+namespace smo {
+
+class ComponentThread;
+
+namespace device {
+
+class DeviceManager;
+
+class DeviceReattacher
+{
+public:
+    DeviceReattacher(
+		DeviceManager& parent, std::shared_ptr<ComponentThread> ioThread);
+    ~DeviceReattacher() = default;
+
+    // Non-copyable
+    DeviceReattacher(const DeviceReattacher&) = delete;
+    DeviceReattacher& operator=(const DeviceReattacher&) = delete;
+
+    // Control methods
+    void start();
+    void stop();
+
+private:
+    void scheduleNextTimeout();
+    void onTimeout(const boost::system::error_code& error);
+
+    DeviceManager &parent;
+    std::shared_ptr<ComponentThread> ioThread;
+    std::atomic<bool> shouldContinue;
+    boost::asio::deadline_timer timer;
+};
+
+} // namespace device
+} // namespace smo
+
+#endif // DEVICEREATTACHER_H