Add unit tests for attr_aug_*
Test attr_aug_reader with :array and :seq
Test attr_aug_reader with :array and string sublabel
Test attr_aug_reader with :hash
Test attr_aug_reader with wrong type
Use method_defined? to make tests work with ruby 1.9
Improve coverage filter for provider.rb
Add unit tests for attr_aug_writer
Add unit tests for attr_aug_writer
Test attr_aug_writer with :array and no sublabel
Test attr_aug_writer with :hash
Test default in :hash