Migrate Database; Add Photographer table

Add additional Exif fields, add Photographer table and nav property
in Photos
Add IReferenceRepository (read only repository) and its derivatives

 On branch master
 Changes to be committed:
   (use "git reset HEAD <file>..." to unstage)

	new file:   PhotoServer.DataAccessLayer/AbstractReferenceRepository.cs
	modified:   PhotoServer.DataAccessLayer/EFPhotoServerDataSource.cs
	modified:   PhotoServer.DataAccessLayer/IPhotoDataSource.cs
	new file:   PhotoServer.DataAccessLayer/IReferenceRepository.cs
	new file:   PhotoServer.DataAccessLayer/Migrations/201305250238399_AddPhotographerRecord.Designer.cs
	new file:   PhotoServer.DataAccessLayer/Migrations/201305250238399_AddPhotographerRecord.cs
	new file:   PhotoServer.DataAccessLayer/Migrations/201305250238399_AddPhotographerRecord.resx
	new file:   PhotoServer.DataAccessLayer/Migrations/201305250337150_AdjustPhotoFields.Designer.cs
	new file:   PhotoServer.DataAccessLayer/Migrations/201305250337150_AdjustPhotoFields.cs
	new file:   PhotoServer.DataAccessLayer/Migrations/201305250337150_AdjustPhotoFields.resx
	new file:   PhotoServer.DataAccessLayer/Migrations/201305252119485_AddShortFieldsToPhotos.Designer.cs
	new file:   PhotoServer.DataAccessLayer/Migrations/201305252119485_AddShortFieldsToPhotos.cs
	new file:   PhotoServer.DataAccessLayer/Migrations/201305252119485_AddShortFieldsToPhotos.resx
	new file:   PhotoServer.DataAccessLayer/Migrations/201305252136028_MakePhotoFieldsNullable.Designer.cs
	new file:   PhotoServer.DataAccessLayer/Migrations/201305252136028_MakePhotoFieldsNullable.cs
	new file:   PhotoServer.DataAccessLayer/Migrations/201305252136028_MakePhotoFieldsNullable.resx
	modified:   PhotoServer.DataAccessLayer/PhotoServer.DataAccessLayer.csproj
	new file:   PhotoServer.DataAccessLayer/PhotographerReferenceRepository.cs
	modified:   PhotoServer.Domain/Distance.cs
	modified:   PhotoServer.Domain/Event.cs
	modified:   PhotoServer.Domain/Photo.cs
	modified:   PhotoServer.Domain/Photographer.cs