get rid of pricedb crud

[Linas Vepstas]

Log Message:
-----------
get rid of pricedb crud

Tags:
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backend-work-1

Modified Files:
--------------
    gnucash/src/backend/file:
        gnc-backend-file.c
        io-gncbin-r.c
        io-gncxml-v1.c
        io-gncxml-v2.c