Describes a binary document. This will get stored in the bulkstore as a multi-part mime document.

General Info
Name	DocumentLink
Owner	obsattachment
Visibility	public
Is Active	false
Is Abstract	false

Relations
Name	Type	Begins	Ends
unnamed	Association	ObsAttachment	DocumentLink

Attributes
Name	Type	Classifier	Default Value
fileName	String	DocumentLink
fileType	DocumentTypes	DocumentLink
href	String	DocumentLink
fileSize	StorageVolume	DocumentLink
documentClass	DocumentClasses	DocumentLink