Handling adding connectors

modeling/scripts/TMLModel.xml

src/main/java/ui/DrawerTMLModeling.java

src/main/java/ui/GTURTLEModeling.java

src/main/java/ui/MainGUI.java

src/main/java/ui/TDiagramPanel.java

src/main/java/ui/TGConnector.java

src/main/java/ui/tmlcompd/TMLCPortConnector.java

src/main/java/ui/tmlcompd/TMLCPrimitiveComponent.java

src/main/java/ui/tmlcompd/TMLCPrimitivePort.java