- move test_self_activate_via_require and
  test_self_activate_deep_unambiguous to
  test_gem_specification.rb file.

- move loaded_spec_names and save_loaded_features
  to rubygems/test_case.rb
- move more activate test cases to
  test_gem_specification.rb
- move some helper methods to rubygems/test_case.rb
move more activate test cases to
test_gem_specification.rb
move more activate test cases to
 test_gem_specification.rb
move more activate test cases to
 test_gem_specification.rb