automatic offset calculation is broken for pixel aligned rendering

[imagico]

When loading a symbol offsets are calculated automatically based on the symbol bounding box. This however does not work together with pixel aligned rendering at the moment - you need to manually specify the correct offset to get proper pixel aligned rendering for most symbols.

[pnorman]

When converting to pixel aligned the patterns are placed at x.5 in the SVG - placing them at x.0 instead would fix this