The new SCMTool ID support was written to use a metaclass to

automatically set an ID at the time a class is created. This actually

broke Power Pack, which makes use of its own metaclasses, and therefore

broke the metaclass chain.
This change erases that metaclass and goes with a new approach, which is

to use a specialized property that will return the correct ID for the

class. This is less invasive and makes for an easier transition, as it

will trigger lookup failures at the time the property is accessed rather

than early in an application's startup.
There's also a fix for CVSTool, which used the wrong attribute to set

the ID, and a fix for the EntryPoint-calculated IDs that were using the

wrong string type.

Review Board and Power Pack unit tests pass