ui: fixed autocompletion issues

* click in autocompletions list causes search
* right arrow for autocompletion
* changed query operator has from '>' to '.' and operator sub from '.' to '+'
* fixed autocompletions to fit to query
and
* fixed spectral layouting endless looping on unconnected node

src/lib/data/graph/filter/GraphFilterConductor.cpp

@@ -29,6 +29,11 @@ void GraphFilterConductor::filter(const QueryTree* tree, const FilterableGraph*
 
 void GraphFilterConductor::filterRecursively(const QueryNode* node, const FilterableGraph* in, FilterableGraph* out) const
 {
+	if (!node)
+	{
+		return;
+	}
+
 	if (node->isOperator())
 	{
 		filterOperatorNode(dynamic_cast<const QueryOperator*>(node), in, out);