Add ability to change all the parts material,unit and model scale in assembly mode

[ptc-4658901]

For current functionality, user have to change the parts material,unit and model scale in part mode one by one. It is a tremendous amount of work if there are a lots of parts in an assembly file.

[bschilling]

Great Idea!  Need functionality to change the units of an assembly and have all of its parts and sub-assemblies change as well.

[ptc-5406964]

The functionality of change the units of an assembly and have all of its parts and sub-assemblies is available in Creo 2.0, please refer to https://www.ptc.com/appserver/cs/view/solution.jsp?n=CS30468&lang=en