[MessageBox] a support for dialog screen usage, custom screen names, support to hide picons, fix auto resize.

menu = [(_("Yes"), 'CALLFUNC', cb_func), (_("No"), 'CALLFUNC', self.ChoiceBoxCB)]
self.ChoiceBoxDialog = self.session.instantiateDialog(MessageBox, text=_('Do you really want to remove the timer ?'), list=menu, skin_name="RemoveTimerQuestion", picon=False)
self.showChoiceBoxDialog()

skin_name=sample
picon=False