Fix duplicated "DMDirc: " in several dialogs.

At some point I simplified StandardDialog to handle prepending DMDirc:
to all dialogs, I apparently didn't alter all the dialogs to take this
into account.

Fixes CLIENT-309

Change-Id: I9ed1937b5f09541c775820b9dc17872fb3dd5b5c
Reviewed-on: http://gerrit.dmdirc.com/2161
Reviewed-by: Chris Smith <chris@dmdirc.com>
Automatic-Compile: DMDirc Build Manager

src/com/dmdirc/addons/ui_swing/dialogs/prefs/URLConfigPanel.java

@@ -262,7 +262,7 @@ public class URLConfigPanel extends JPanel implements
     public void actionPerformed(final ActionEvent e) {
         if (e.getSource() == add) {
             new StandardInputDialog(parentWindow, ModalityType.MODELESS,
-                    "DMDIRC: New URL handler",
+                    "New URL handler",
                     "Please enter the name of the new protocol.",
                     new URLProtocolValidator()) {
 

src/com/dmdirc/addons/ui_swing/wizard/firstrun/SwingFirstRunWizard.java

@@ -68,7 +68,7 @@ public final class SwingFirstRunWizard implements WizardListener,
             final SwingController controller) {
         this.controller = controller;
 
-        wizardDialog = new WizardDialog("DMDirc: Setup wizard",
+        wizardDialog = new WizardDialog("Setup wizard",
                 new ArrayList<Step>(), parentWindow,
                 ModalityType.APPLICATION_MODAL);
         wizardDialog.setIconImage(new IconManager(IdentityManager