Patch from Chris Shoemaker to convert all the string cache users to use

[David Hampton]

Log Message:
-----------
Patch from Chris Shoemaker to convert all the string cache users to
use the public access functions.  Consolidate all the CACHE_INSERT and
CACHE_REMOVE macros into one place.

Tags:
----
gnucash-gnome2-dev

Modified Files:
--------------
    gnucash:
        ChangeLog
    gnucash/src/app-utils:
        gnc-component-manager.c
    gnucash/src/business/business-core:
        gncAddress.c
        gncBillTerm.c
        gncCustomer.c
        gncEmployee.c
        gncEntry.c
        gncInvoice.c
        gncJob.c
        gncOrder.c
        gncTaxTable.c
        gncVendor.c
    gnucash/src/business/business-core/test:
        test-customer.c
        test-employee.c
        test-job.c
        test-vendor.c
    gnucash/src/engine:
        Transaction.c
        gnc-commodity.c
        gnc-engine.c
        gnc-pricedb.c
        kvp_frame.c
        qofid.c
        qofquery-deserial.c
    gnucash/src/engine/test:
        test-commodities.c
    gnucash/src/gnome-utils:
        QuickFill.c