Integration of the path planner into rtabmap's memory management to actually retrieve nodes on the planned path on the graph.

Added Rtabmap::clearPath(), Rtabmap::computePath(), Rtabmap::getPathGoalId() and Rtabmap::updateGoalIndex() methods.
Added virtual links when path retrieval is activated (virtual links are not saved to database and removed when the path goal is reached).
New parameters: RGBD/GoalReachedRadius and RGBD/MaxAnticipatedNodes
Refactored how loop closure hypotheses are selected (fixed ratio between consecutive hypotheses, not the last loop closure).
Updated getNodesInRadius() to use all filtered scans.
GUI: window can be saved/loaded maximized
GUI: saving Graph View parameters to config.ini

corelib/src/Signature.cpp

@@ -149,6 +149,21 @@ void Signature::removeLink(int idTo)
 	}
 }
 
+void Signature::removeVirtualLinks()
+{
+	for(std::map<int, Link>::iterator iter=_links.begin(); iter!=_links.end();)
+	{
+		if(iter->second.type() == Link::kVirtualClosure)
+		{
+			_links.erase(iter++);
+		}
+		else
+		{
+			++iter;
+		}
+	}
+}
+
 float Signature::compareTo(const Signature & s) const
 {
 	float similarity = 0.0f;