Revert "move libthread to libstb-hal"

This reverts commit 95ee7f9e98.

common/thread_abstraction.h

@@ -0,0 +1,25 @@
+#ifndef _SIMPLETHREAD_ABSTRACTION_H
+#define _SIMPLETHREAD_ABSTRACTION_H
+
+#include <pthread.h>
+
+class SimpleThread
+{
+	bool mIsRunning;
+	pthread_t mThread;
+
+	static void* runThread(void*);
+	SimpleThread(const SimpleThread&);
+	const SimpleThread& operator=(const SimpleThread&);
+
+	public:
+		SimpleThread();
+		~SimpleThread();
+		void startThread();
+		void joinThread();
+
+	protected:
+		virtual void run() = 0;
+};
+
+#endif