BF - fix voxel size computation in LocalTracking
BF - fix voxel size computation in LocalTracking

JohnGriffiths/dipy,nilgoyyou/dipy,FrancoisRheaultUS/dipy,matthieudumont/dipy,mdesco/dipy,matthieudumont/dipy,Messaoud-Boudjada/dipy,beni55/dipy,jyeatman/dipy,oesteban/dipy,mdesco/dipy,StongeEtienne/dipy,villalonreina/dipy,nilgoyyou/dipy,FrancoisRheaultUS/dipy,sinkpoint/dipy,jyeatman/dipy,demianw/dipy,Messaoud-Boudjada/dipy,rfdougherty/dipy,StongeEtienne/dipy,beni55/dipy,villalonreina/dipy,oesteban/dipy,demianw/dipy,rfdougherty/dipy,sinkpoint/dipy,JohnGriffiths/dipy