Adding Help Window

src/main/java/help/HelpEntry.java

src/main/java/help/HelpManager.java

src/main/java/ui/GTURTLEModeling.java

src/main/java/ui/MainGUI.java

src/main/java/ui/tree/DiagramTreeModel.java

src/main/java/ui/tree/DiagramTreeRenderer.java

src/main/java/ui/tree/HelpTree.java

src/main/java/ui/tree/JDiagramTree.java

src/main/java/ui/window/JFrameHelp.java

src/main/resources/help/helpTable.txt

ttool/src/test/java/help/HelpTests.java