gnucash maint: Multiple changes pushed

[Christopher Lam]

Updated	 via  https://github.com/Gnucash/gnucash/commit/2c04ae31 (commit)
	 via  https://github.com/Gnucash/gnucash/commit/f6bfdabd (commit)
	 via  https://github.com/Gnucash/gnucash/commit/241f1f92 (commit)
	 via  https://github.com/Gnucash/gnucash/commit/497e18c3 (commit)
	from  https://github.com/Gnucash/gnucash/commit/ca759fb4 (commit)



commit 2c04ae310b6612e59dc2ca9dfec0002bda4c4a9f
Author: Christopher Lam <christopher.lck at gmail.com>
Date:   Thu May 9 21:05:51 2019 +0800

    [trep-engine] allow #:custom-source-accounts kwarg
    
    specifying #:custom-source-accounts will override the (opt-val
    "Accounts" "Accounts") option to specify source accounts
    
    This is useful for custom-reports which may need multiple source
    accounts. eg. VAT/GST report (still in development).

commit f6bfdabd3ed5d0d75f27e1e07f6c33bbf6f6eb50
Author: Christopher Lam <christopher.lck at gmail.com>
Date:   Thu May 9 21:03:58 2019 +0800

    [trep-engine] allow #f for friendly-fn
    
    During defition of custom-calculated-cells, we should allow #f as
    friendly-fn which will disable it.

commit 241f1f927439b05dc3e9d4a350e7d7e8ef545063
Author: Christopher Lam <christopher.lck at gmail.com>
Date:   Thu Jun 13 21:09:31 2019 +0800

    [test-transaction] add csv test
    
    runs report with csv output
    test csv output matches expectation

commit 497e18c36ed59873f175ab6d67e1a2f28f26894d
Author: Christopher Lam <christopher.lck at gmail.com>
Date:   Fri May 3 13:19:08 2019 +0800

    [trep-engine] allow csv export of grand-totals
    
    This commit enables CSV export of split monetary columns and
    grand-totals.
    
    Sample CSV output:
    "from","2018-01-01"
    "to","2018-03-31"
    "Debit",4270.88
    "Credit",8314.44
    
    * Note dates are iso-format strings.
    
    * If a grand-total has multiple currencies, all will be listed
      e.g. grand-total 100GBP + 50USD will show as: "Amount",100.0,50.0
    
    * Dual subtotals (debit/credit) will not be exportable as CSVs because
      they are not merged



Summary of changes:
 gnucash/report/report-system/trep-engine.scm       | 103 +++++++++++++++++++--
 .../standard-reports/income-gst-statement.scm      |  11 ++-
 .../standard-reports/test/test-transaction.scm     |  34 ++++++-
 3 files changed, 136 insertions(+), 12 deletions(-)