checkpoint partially working code

[Linas Vepstas]

Log Message:
-----------
checkpoint partially working code

Tags:
----
backend-work-1

Modified Files:
--------------
    gnucash/src/engine:
        Account.c
        Period.c
        Transaction.c
        gnc-pricedb-p.h
        gnc-pricedb.c
        qofbackend-p.h

Added Files:
-----------
    gnucash/src/engine:
        qof-be-utils.h

Removed Files:
-------------
    gnucash/src/engine:
        gnc-be-utils.h