r16827: Factor out some code into common samdb functions:

r16827: Factor out some code into common samdb functions:
 - creation of ForeignSecurityPrincipals
 - template duplication code

Rework much of the LSA server to pass the RPC-LSA test.  Much of the
server code was untested.  In implementing the LSA Accounts feature, I
have opted to have it only create entires when privilages are applied,
and not to delete entries, but to delete the privilages.

We skip some parts of the test, but it is much better than not testing
it at all.

Andrew Bartlett
(This used to be commit 10eeea6da465564ed9f785d06e2d2ed06cfe29a4)