Fixes many data layer issues: 27044, 27045, 24237, 27042, 27043, 27046, 27070, 27072, 27073, 27074 [TFS Changeset #66135]
[TFS Changeset #65677]
Adds support for new 4.1 content schema [TFS Changeset #63631]
Created 4.1.0 branch [TFS Changeset #55082]