Bug fixes in the scale bar, actor settings adjusted
Bug fixes in the scale bar, actor settings adjusted

It was showing the distance squared, may as well use new vtkVectors
with their operators. The axis actor behaves better when it does not
calculate "nice" numbers, as it hides quite significant shifts.

yijiang1/tomviz,mathturtle/tomviz,OpenChemistry/tomviz,cryos/tomviz,cryos/tomviz,OpenChemistry/tomviz,cjh1/tomviz,OpenChemistry/tomviz,mathturtle/tomviz,thewtex/tomviz,mathturtle/tomviz,cryos/tomviz,yijiang1/tomviz,thewtex/tomviz,Hovden/tomviz,OpenChemistry/tomviz,thewtex/tomviz,Hovden/tomviz,cjh1/tomviz,cjh1/tomviz