Current design has 1 instance of FsClassRegistry per Cas per View.
With the redesign going on for JCas we no longer need one per View.
We don't even need one per Cas. CASes in a pool, sharing the same type
system, can share generators.
Anyone object if I change the impl to move the FSClassReg instance into
the typeSystemImpl instance, since these can be shared by CASes (and I
hope that they are when it's known the CASes are using the same type
system - such as a Cas Pool - if they're not, please let me know).
We can still keep a direct pointer to the shared instance from the CAS
instance to the FSClassReg instance, to reduce by 1 deref the path
traversed when using the generators (or does everybody think that's silly?).
-Marshall
