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/transactionview.h

@@ -22,6 +22,7 @@ QT_END_NAMESPACE
 class TransactionView : public QWidget
 {
     Q_OBJECT
+
 public:
     explicit TransactionView(QWidget *parent = 0);