Minor bug in PathStrokeStype::createDashedStroke()

[pflugshaupt]

I found a bug in PathStrokeStype::createDashedStroke(). While going through the source path step by step it currently calls startNewSubPath for each step, which is wrong and wastes time and memory.

PathStrokeStype::createDashedStroke() do not call startNewSubPath for every gap step.

[reuk]

Thanks! Added here:

PathStrokeType: Avoid unnecessarily starting new subpaths