Make it very clear when on testnet (green icon, add [testnet] to title)

src/qt/bitcoin.qrc

@@ -22,6 +22,8 @@
         <file alias="editpaste">res/icons/editpaste.png</file>
         <file alias="editcopy">res/icons/editcopy.png</file>
         <file alias="add">res/icons/add.png</file>
+        <file alias="bitcoin_testnet">res/icons/bitcoin_testnet.png</file>
+        <file alias="toolbar_testnet">res/icons/toolbar_testnet.png</file>
     </qresource>
     <qresource prefix="/images">
         <file alias="about">res/images/about.png</file>

src/qt/bitcoingui.cpp

@@ -182,6 +182,17 @@ void BitcoinGUI::setClientModel(ClientModel *clientModel)
 {
     this->clientModel = clientModel;
 
+    if(clientModel->isTestNet())
+    {
+        setWindowTitle(tr("Bitcoin [testnet]"));
+        setWindowIcon(QIcon(":icons/bitcoin_testnet"));
+        if(trayIcon)
+        {
+            trayIcon->setToolTip(tr("Bitcoin [testnet]"));
+            trayIcon->setIcon(QIcon(":/icons/toolbar_testnet"));
+        }
+    }
+
     // Keep up to date with client
     setNumConnections(clientModel->getNumConnections());
     connect(clientModel, SIGNAL(numConnectionsChanged(int)), this, SLOT(setNumConnections(int)));
@@ -229,6 +240,7 @@ void BitcoinGUI::createTrayIcon()
 
     trayIcon = new QSystemTrayIcon(this);
     trayIcon->setContextMenu(trayIconMenu);
+    trayIcon->setToolTip("Bitcoin client");
     trayIcon->setIcon(QIcon(":/icons/toolbar"));
     connect(trayIcon, SIGNAL(activated(QSystemTrayIcon::ActivationReason)),
             this, SLOT(trayIconActivated(QSystemTrayIcon::ActivationReason)));

src/qt/clientmodel.cpp

@@ -39,6 +39,11 @@ void ClientModel::update()
     emit numBlocksChanged(getNumBlocks());
 }
 
+bool ClientModel::isTestNet() const
+{
+    return fTestNet;
+}
+
 bool ClientModel::inInitialBlockDownload() const
 {
     return IsInitialBlockDownload();

src/qt/clientmodel.h

@@ -22,6 +22,8 @@ public:
     int getNumConnections() const;
     int getNumBlocks() const;
 
+    // Return true if client connected to testnet
+    bool isTestNet() const;
     // Return true if core is doing initial block download
     bool inInitialBlockDownload() const;
     // Return conservative estimate of total number of blocks, or 0 if unknown