qt: remove awkward way of setting GUI pages

Selecting the button for a pages was going through bitcoingui->walletframe->walletview->bitcoingui.
Because of this, the actions for the pages had to be exposed on the BitcoinGUI object.

src/qt/walletframe.cpp

@@ -44,7 +44,8 @@ bool WalletFrame::addWallet(const QString& name, WalletModel *walletModel)
     walletView->setWalletModel(walletModel);
     walletView->showOutOfSyncWarning(bOutOfSync);
 
-    walletView->gotoOverviewPage(); /* XXX we should go to the currently selected page */
+     /* TODO we should goto the currently selected page once dynamically adding wallets is supported */
+    walletView->gotoOverviewPage();
     walletStack->addWidget(walletView);
     mapWalletViews[name] = walletView;
 
@@ -65,6 +66,16 @@ bool WalletFrame::setCurrentWallet(const QString& name)
     return true;
 }
 
+bool WalletFrame::removeWallet(const QString &name)
+{
+    if (mapWalletViews.count(name) == 0)
+        return false;
+
+    WalletView *walletView = mapWalletViews.take(name);
+    walletStack->removeWidget(walletView);
+    return true;
+}
+
 void WalletFrame::removeAllWallets()
 {
     QMap<QString, WalletView*>::const_iterator i;