Fixed some bugs with block struct allocation.
Fixed some bugs with block struct allocation.

dpellegr/sixtracklib,hussainmkj/sixtracklib,dpellegr/sixtracklib,hussainmkj/sixtracklib,SixTrack/SixTrackLib,SixTrack/SixTrackLib,dpellegr/sixtracklib,SixTrack/SixTrackLib,SixTrack/SixTrackLib