- prefer csorted() method for const access since it ensures that the
return values are also const pointers (for example) even if
the object itself can be accessed as a non-const.
- the csorted() method already existed for HashTable and
objectRegistry, but now added to IOobjectList for method name
consistency (even although the IOobjectList only has a const-access
version)
ENH: objectRegistry with templated strict lookup
- for lookupClass and csorted/sorted. Allows isType restriction as a
compile-time specification.
