* new file lib/UnlockGuard.h — unlock_guard is for unlocking a mutex for the scope time (RAII)

* all lock/unlock and unlock/lock pairs are done by RAII guards now
* fixed two possible crashes at the end of battle when last stack was killed by spell. That should fix #749 and #752.
* fixed a very nasty race condition, eliminating possible deadlock at the start of battle when human hero has tactics
* fixed #422

lib/Interprocess.h

@@ -28,9 +28,10 @@ struct ServerReady
 
 	void setToTrueAndNotify()
 	{
-		mutex.lock();
-		ready = true;
-		mutex.unlock();
+		{
+			boost::unique_lock<boost::interprocess::interprocess_mutex> lock(mutex); 
+			ready = true;
+		}
 		cond.notify_all();
 	}
 };