BnfDataBaseActivity: query min length 4 -> 3
Make Author and Work subclasses of DataObject
Add a ViewObjectActivity abstract class

It gathers common code of the View* activities and common abstract
methods to be implemented.
DataLoader: use ViewObjectActivity
Add a general DataLoaderCallbacks class

It uses the general ViewObjectActivity and can then replace all the
object-specific *DataLoaderCallbacks.
Make ViewAuthorActivity extend ViewObjectActivity
Remove the obsolete AuthorDataLoaderCallbacks
Work layout: remove useless attributes
Make ViewWorkActivity extend ViewObjectActivity
Remove the obsolete WorkDataLoaderCallbacks
Organization layout: <RelativeLayout> -> <merge>
Organization layout: add new strings and new views
Add a POJO representing an organization

It offers easy access to the data of the JSONObject provided to the
constructor.
Make ViewOrganizationActivity extend ViewObjectActivity
Remove the obsolete OrganizationDataLoaderCallbacks
Change access modifiers in the View* activities
Add a general ImageLoaderCallbacks

It is meant to replace the now obsolete *ImageLoaderCallbacks.
View* activities: use the new ImageLoaderCallbacks
Remove the obsolete *ImageLoaderCallbacks
Do not use DataObject anymore

It was made by error and is actually useless.