Adding System.Compo... System.Ident... System.Numer... System.Runti...

Adding reference source for
System.ComponentModel.DataAnnotations
System.IdentityModel
System.IdentityModel.Selectors
System.Numerics
System.Runtime.Caching
System.Runtime.Serialization
Merge pull request #1 from Microsoft/master

Adding System.Compo... System.Ident... System.Numer... System.Runti...