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/addressbookpage.cpp

@@ -8,15 +8,15 @@
 #include "csvmodelwriter.h"
 #include "guiutil.h"
 
+#ifdef USE_QRCODE
+#include "qrcodedialog.h"
+#endif
+
 #include <QSortFilterProxyModel>
 #include <QClipboard>
 #include <QMessageBox>
 #include <QMenu>
 
-#ifdef USE_QRCODE
-#include "qrcodedialog.h"
-#endif
-
 AddressBookPage::AddressBookPage(Mode mode, Tabs tab, QWidget *parent) :
     QDialog(parent),
     ui(new Ui::AddressBookPage),