Fixed width Data pane

[m_seitzz]

Right now, the Info pane has a fixed, user adjustable width. When the XnView MP window is resized horizontally, XnView MP will try to keep the Info pane at its current width, and only resize the Data pane.

It would be very helpful if the Data pane could be set to a fixed size. E.g. with "Layout 2", one could adjust the width of the Data pane in such a way that the thumbnail view is two thumbnails wide. On resizing the XnView MP window, I'd like to keep the Data pane two thumbnails wide and have the Info pane with the preview resized instead.