Added Controller, interfaces, fixtures and entities for product attributes
Implemented get, cget and delete for product attributes
Cleanup code
Fixed ProductControllerTest
Added AttributeValue entity and exceptions
Implemented api for creating and editing attribute values
Implemented delete for attribute values
fixed tests
Added tests for attributes and attributeValues
Code improvements
Renamed attribute and attributeValue exceptions
Added some phpdoc to exceptions
Added tests and fixed attibuteVlalues api
Renamed ValuesController to ValueController
Renamed nodes in attribute-types.xml
Added functionality to AttributeManager to get all attributes for a given id
Extended tests and declared missing variables
fixed tests
Merge branch 'feature/attributesetup' into develop