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/optionsdialog.cpp

@@ -10,8 +10,6 @@
 #include <QIntValidator>
 #include <QLocale>
 #include <QMessageBox>
-#include <QRegExp>
-#include <QRegExpValidator>
 
 OptionsDialog::OptionsDialog(QWidget *parent) :
     QDialog(parent),