Set forceSmartPSDPixelScaling to true if layer is a placed smart object.

Photoshop returns an error to getLayerPixmap() if the layer is a linked smart object, links to another PSD and has scaling options set. This is a workaround until the root bug is fixed in PS.
Can you explain to me what's going on here? Is it sometimes the case that there's a smart object layer but `rawLayer.type` is NOT "smartObjectLayer"? If so, it seems like we have a bug in the doc info coming from PS, and we should fix that instead of this workaround.