Implement groups for contacts.
Implement groups for contacts.

Group changed signals in the backend case is still broken.

kaltsi/qt-mobility,kaltsi/qt-mobility,qtproject/qt-mobility,tmcguire/qt-mobility,tmcguire/qt-mobility,KDE/android-qt-mobility,tmcguire/qt-mobility,kaltsi/qt-mobility,enthought/qt-mobility,enthought/qt-mobility,kaltsi/qt-mobility,enthought/qt-mobility,qtproject/qt-mobility,enthought/qt-mobility,KDE/android-qt-mobility,qtproject/qt-mobility,enthought/qt-mobility,tmcguire/qt-mobility,enthought/qt-mobility,tmcguire/qt-mobility,qtproject/qt-mobility,KDE/android-qt-mobility,qtproject/qt-mobility,kaltsi/qt-mobility,KDE/android-qt-mobility,qtproject/qt-mobility,kaltsi/qt-mobility