[2.5] Locking GridPanel and group commands.

Hi Daniil,

I would like to provide some issues and omissions in Grouping command.

Both CommandColumn and ImageCommandColumn
1) Command columns renders only on the right side of the locking grid. It would be nice if commands can be managed in this case. If not, I think, the left side will be preferred.

ImageCommandColumn:
1) GroupImageCommand doesn't render in locking grid.

I would be grateful if this changes/fixes will be applied not only for v3.x (v2.5.x too)

Thanks