Bitcoin-Qt: massive header and cpp cleanup

- try to enforce the same style to all Qt related files
- remove unneeded includes from the files
- add missing Q_OBJECT, QT_BEGIN_NAMESPACE / QT_END_NAMESPACE
- prepares for a pull-req to include Qt5 compatibility

src/qt/paymentserver.cpp

@@ -2,14 +2,15 @@
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <QApplication>
+
 #include "paymentserver.h"
+
 #include "guiconstants.h"
 #include "ui_interface.h"
 #include "util.h"
 
-#include <QApplication>
 #include <QByteArray>
-#include <QCoreApplication>
 #include <QDataStream>
 #include <QDebug>
 #include <QFileOpenEvent>
@@ -59,7 +60,7 @@ bool PaymentServer::ipcSendCommandLine()
 {
     bool fResult = false;
 
-    const QStringList& args = QCoreApplication::arguments();
+    const QStringList& args = qApp->arguments();
     for (int i = 1; i < args.size(); i++)
     {
         if (!args[i].startsWith(BITCOIN_IPC_PREFIX, Qt::CaseInsensitive))