ui: Added on-screen search feature (issue #79)

* Use menu action "Edit -> Find in View" or Ctrl + D
* UI displayed as search bar at bottom of main window
* Hide search bar with ECS or close button
* Entering a query searches in name of graph nodes and code contents of code view
* Use Enter to iterate through matches, well move match into view in graph and code view
* Checkboxes allow for adding/removing results for certain views
* Create Bookmark shortcut is now CTRL + S

bug id = 79

src/lib_gui/qt/view/QtCodeView.h

@@ -18,6 +18,13 @@ public:
 	virtual void initView();
 	virtual void refreshView();
 
+	// ScreenSearchResponder implementation
+	virtual bool isVisible() const;
+	virtual void findMatches(ScreenSearchSender* sender, const std::string& query);
+	virtual void activateMatch(size_t matchIndex);
+	virtual void deactivateMatch(size_t matchIndex);
+	virtual void clearMatches();
+
 	// CodeView implementation
 	virtual void clear();