Fetch added and updated timestamps from the image object if they exist
Made the database tests run quicker
Added a fields property that will be used by formatters to choose which fields from the model that will be displayed
Set the fields in the model if a fields query parameter is present
Use the fields property to filter fields
Added a scenario for the fields query parameter
Added a note regarding the fields query parameter
Updated the ChangeLog
Merge pull request #204 from christeredvartsen/choose-fields-to-display

Images resource should be able to retrieve only specific fields