Apparently I missed a lot of alterations in the previous commits. The situation now is this: secret sharing and access policy notions are totally abstracted away; there is an implementation of a BL canonical access policy and corresponding secret sharing implemented with respective tests running. There is a tree implementation for use with Shamir Trees and a more general BL. There are tests but the latest changes have made them probably not compile or not run satisfactorily. Same can be applied to shamir2.