update CClientUIInterface and remove orphan Wx stuff

- fix ThreadSafeMessageBox always displays error icon
- allow to specify MSG_ERROR / MSG_WARNING or MSG_INFORMATION without a
  custom caption / title
- allow to specify CClientUIInterface::ICON_ERROR / ICON_WARNING and
  ICON_INFORMATION (which is default) as message box icon
- remove CClientUIInterface::OK from ThreadSafeMessageBox-calls, as
  the OK button will be set as default, if none is specified
- prepend "Bitcoin - " to used captions
- rename BitcoinGUI::error() -> BitcoinGUI::message() and add function
  documentation
- change all style parameters and enum flags to unsigned
- update code to use that new API

- update Client- and WalletModel to use new BitcoinGUI::message() and
  rename the classes error() method into message()
- include the possibility to supply the wanted icon for messages from
  Client- and WalletModel via "style" parameter

src/qt/bitcoingui.cpp

@@ -25,6 +25,7 @@
 #include "notificator.h"
 #include "guiutil.h"
 #include "rpcconsole.h"
+#include "ui_interface.h"
 
 #ifdef Q_OS_MAC
 #include "macdockiconhandler.h"
@@ -366,8 +367,8 @@ void BitcoinGUI::setClientModel(ClientModel *clientModel)
         setNumBlocks(clientModel->getNumBlocks(), clientModel->getNumBlocksOfPeers());
         connect(clientModel, SIGNAL(numBlocksChanged(int,int)), this, SLOT(setNumBlocks(int,int)));
 
-        // Report errors from network/worker thread
-        connect(clientModel, SIGNAL(error(QString,QString,bool)), this, SLOT(error(QString,QString,bool)));
+        // Receive and report messages from network/worker thread
+        connect(clientModel, SIGNAL(message(QString,QString,bool,unsigned int)), this, SLOT(message(QString,QString,bool,unsigned int)));
 
         overviewPage->setClientModel(clientModel);
         rpcConsole->setClientModel(clientModel);
@@ -381,8 +382,8 @@ void BitcoinGUI::setWalletModel(WalletModel *walletModel)
     this->walletModel = walletModel;
     if(walletModel)
     {
-        // Report errors from wallet thread
-        connect(walletModel, SIGNAL(error(QString,QString,bool)), this, SLOT(error(QString,QString,bool)));
+        // Receive and report messages from wallet thread
+        connect(walletModel, SIGNAL(message(QString,QString,bool,unsigned int)), this, SLOT(message(QString,QString,bool,unsigned int)));
 
         // Put transaction list in tabs
         transactionView->setModel(walletModel);
@@ -592,15 +593,50 @@ void BitcoinGUI::setNumBlocks(int count, int nTotalBlocks)
     progressBar->setToolTip(tooltip);
 }
 
-void BitcoinGUI::error(const QString &title, const QString &message, bool modal)
+void BitcoinGUI::message(const QString &title, const QString &message, bool modal, unsigned int style)
 {
-    // Report errors from network/worker thread
-    if(modal)
-    {
-        QMessageBox::critical(this, title, message, QMessageBox::Ok, QMessageBox::Ok);
-    } else {
-        notificator->notify(Notificator::Critical, title, message);
+    QString strTitle = tr("Bitcoin") + " - ";
+    // Default to information icon
+    int nMBoxIcon = QMessageBox::Information;
+    int nNotifyIcon = Notificator::Information;
+
+    // Check for usage of predefined title
+    switch (style) {
+    case CClientUIInterface::MSG_ERROR:
+        strTitle += tr("Error");
+        break;
+    case CClientUIInterface::MSG_WARNING:
+        strTitle += tr("Warning");
+        break;
+    case CClientUIInterface::MSG_INFORMATION:
+        strTitle += tr("Information");
+        break;
+    default:
+        strTitle += title; // Use supplied title
     }
+
+    // Check for error/warning icon
+    if (style & CClientUIInterface::ICON_ERROR) {
+        nMBoxIcon = QMessageBox::Critical;
+        nNotifyIcon = Notificator::Critical;
+    }
+    else if (style & CClientUIInterface::ICON_WARNING) {
+        nMBoxIcon = QMessageBox::Warning;
+        nNotifyIcon = Notificator::Warning;
+    }
+
+    // Display message
+    if (modal) {
+        // Check for buttons, use OK as default, if none was supplied
+        QMessageBox::StandardButton buttons;
+        if (!(buttons = (QMessageBox::StandardButton)(style & CClientUIInterface::BTN_MASK)))
+            buttons = QMessageBox::Ok;
+
+        QMessageBox mBox((QMessageBox::Icon)nMBoxIcon, strTitle, message, buttons);
+        mBox.exec();
+    }
+    else
+        notificator->notify((Notificator::Class)nNotifyIcon, strTitle, message);
 }
 
 void BitcoinGUI::changeEvent(QEvent *e)