Align images by component

[fxkr]

Currently image alignment is done graphically by determining a bounding box on the dimension layer.

However, it might be possible to have the user specify a component, get that components position from the XML data and align by that. The hard part is probably converting component positions to pixel coordinates (which unit? where is the origin?). Renamed components may or may not be a problem too.

This would allow useful diffs when the entire ciruit has been moved around on the board.