#Issue 70: Implement standard diagram editing keys

src/main/java/ui/ActionPerformer.java

src/main/java/ui/ArrowListener.java

src/main/java/ui/JMenuBarTurtle.java

src/main/java/ui/JToolBarMainTurtle.java

src/main/java/ui/ModeManager.java

src/main/java/ui/TDiagramMouseManager.java

src/main/java/ui/TDiagramPanel.java

src/main/java/ui/TGComponent.java

src/main/java/ui/TGUIAction.java

src/main/java/ui/util/IconManager.java

...urces/ui/util/toolbarButtonGraphics/navigation/Left16.gif

...rces/ui/util/toolbarButtonGraphics/navigation/Right16.gif