[mythtv] Ticket #2839: Enable virtual keyboard for ComboBox

[Matthew Wire]

I've just submitted a patch to enable the virtual keyboard for editable
comboboxes.  This removes another need for using a computer keyboard.

At the moment it segfaults when sending keys to the combobox.  I think
the problem is that I'm using the wrong pointer here:
MythComboBox *par = (MythComboBox *)m_parentEdit; 

Can anyone point me in the right direction?

Thanks,
Matthew