Ed Huff's (May) patch re: quarterly support in the transaction report +

[Joshua Sled]

Log Message:
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Ed Huff's (May) patch re: quarterly support in the transaction report + date-handling refactoring.

Tags:
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gnucash-gnome2-dev

Modified Files:
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    gnucash/src/report/standard-reports:
        transaction.scm
    gnucash:
        ChangeLog
    gnucash/src/app-utils:
        app-utils.scm
        date-utilities.scm