Updated gnucash to 2.6.17.

2.6.17 - 2 July 2017

The following bugs are fixed:
      Bug 603379 - Prevent changing some Account Options if it has transactions
                  Followup: Relax the account type change restrictions again.
  In the new implementation account types can'tz be changed
  for an account with splits:
  - if the change woud force a commodity change
    (to/from normal accounts from/to stock related accounts)
  - for immutable accounts
  At the time of this commit the following account types are
  considered immutable:
  - Accounts Receivable
  - Accounts Payable
  - Trading accounts
      Bug 776396 - Foreign currency reports, amounts are not aligned correctly
                  Improve the styling of the table element used for foreign
  currencies in the Balance sheet report so they end up
  aligned with the other currencies.
      Bug 780845 - link in github repo README file needs correction/editing
      Bug 780889 - Split-register transactions result in invalid price:type
                  "transaction": Add 'transaction' to the schema and document
  it in gnc-pricedb.h.
      Bug 781634 - Alert on missing account currency when opening account
          Also separate translatable commodity namespace strings
                  from those used in storage:
  There is now a separate GNC_COMMODITY_NS_ISO_GUI
  label to be used everywhere the user needs to read
  'Currency namespace'. It's currently set to
  'Currencies' and can be translated.

      Bug 782274 - Transactions produced by Transfer Funds or Process Payment
                  dialogs sort to beginning of day and do not honor NUM field
  for custom sorting.
      Bug 782897 - Stock Split Assistant crashes GnuCash if you enter a New
                  Price and that already exists in the Price DB
      Bug 783095 - gnucash-2.6.16 segfaults on startup
      Bug 784317 - typo in 'import customers or vendors from text file' dialog

Other repairs not marked as bugs in git:
      Properly define the template namespace rather than using a local string
        everywhere
      Correctly store time64 0 in the SQL backend: The SQL backend ignored
        time64 0 when saving dates. time64 is a perfectly valid timestamp
(1970-01-01 00:00:00) and should be stored.
      Clamp time64 values passed to GDateTime functions to the valid range.
        Fixes a bug reported on the mailing list wherein a date of 0000-00-00
        in a MySql database would crash GnuCash. Such dates may come from a bad
        conversion of 1970-01-01 or from a crash.
      Add XSU to iso-4217-currencies
      Some banks include additional purpose information for a transaction in
        non-swift-section 17 (aka transaction text). If available, this
transaction text is put in front of the other purpose texts to provide
full transaction information. Adds a preference to control import
behaivour of transaction text.

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(wiz)