Fix broken link for active bugs on the CPAN Request Tracker
Minor tidy-ups etc

- Rewrite require/import to be in the order in which they happen.
- mk_*_accessor() are actually protected, not public -- they will be called
  classes that subclass this, but not from outside the class hierarchy.
- _mk_accessor() and attrs() are called from the accessors installed into
  subclasses so must be protected rather than private, although the former
  is undocumented, hence the leading underscore.
Add Class::Data::Inheritable::Translucent::Object