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/clientmodel.h

@@ -24,6 +24,7 @@ enum BlockSource {
 class ClientModel : public QObject
 {
     Q_OBJECT
+
 public:
     explicit ClientModel(OptionsModel *optionsModel, QObject *parent = 0);
     ~ClientModel();
@@ -66,6 +67,7 @@ private:
 
     void subscribeToCoreSignals();
     void unsubscribeFromCoreSignals();
+
 signals:
     void numConnectionsChanged(int count);
     void numBlocksChanged(int count, int countOfPeers);