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/editaddressdialog.h

@@ -3,15 +3,15 @@
 
 #include <QDialog>
 
-QT_BEGIN_NAMESPACE
-class QDataWidgetMapper;
-QT_END_NAMESPACE
-
 namespace Ui {
     class EditAddressDialog;
 }
 class AddressTableModel;
 
+QT_BEGIN_NAMESPACE
+class QDataWidgetMapper;
+QT_END_NAMESPACE
+
 /** Dialog for editing an address and associated information.
  */
 class EditAddressDialog : public QDialog