CODE: support for multi-model sdf files
CODE: support for multi-model sdf files

including asTrajectory & firstModelOnly options

j0kaso/ngl,arose/ngl,fredludlow/ngl,j0kaso/ngl,j0kaso/ngl,fredludlow/ngl,fredludlow/ngl,arose/ngl,fredludlow/ngl,arose/ngl,arose/ngl