Chat function worked!

src/GUI/ChatScreen.java

src/GUI/DrawingArea.java

src/GUI/PaintGUI.java

src/GUI/StartScreen.java

src/GUI/ToolBar.java

src/client/ChatUpdate.java

src/client/Client.java

src/client/ClientCanvas.java

src/client/DrawingUpdate.java

src/remote/IChatController.java

src/remote/IChatUpdate.java

src/remote/IClientUpdate.java

src/remote/IUpdateController.java

src/server/ChatController.java

src/server/ClientController.java

src/server/DrawingController.java

src/server/Server.java

src/server/User.java