ui: Show call graphs, inheritance trees and include trees for active symbol (issue 249 337)

* Added TrailLayouter with Sugiyama dependency layouting
* Layouter supports horizontal and vertical layouts
* Added basic ui to graph view for showing incoming and outgoing paths
* Added depth slider, with infinity at maximum
* Disable trail ui when not available
* Added trail messages to undo stack and only use last one when undoing
* Added QtGraphLineBezier for trail graphs and refactored other line types
* Disabled edge activation for trail layouts, shown only visually
* Highlight all connected edges when hovering a node in trail layout
* Use different color when highlighting call edges for better contrast
* Fixed BucketLayouter issue when edge does not leave node
* Increased click area for angled edges

bug id = 249 337

fortune cookie message = Answer just what the heart prompts to you.

src/lib/data/graph/Graph.cpp

@@ -3,6 +3,7 @@
 #include "utility/logging/logging.h"
 
 Graph::Graph()
+	: m_trailMode(TRAIL_NONE)
 {
 }
 
@@ -285,6 +286,16 @@ Token* Graph::getTokenById(Id id) const
 	return token;
 }
 
+Graph::TrailMode Graph::getTrailMode() const
+{
+	return m_trailMode;
+}
+
+void Graph::setTrailMode(TrailMode trailMode)
+{
+	m_trailMode = trailMode;
+}
+
 void Graph::print(std::ostream& ostream) const
 {
 	ostream << "Graph:\n";