gnucash maint: 797171 - Allow multiple credit/debit columns to be selected

[Geert Janssens]

Updated	 via  https://github.com/Gnucash/gnucash/commit/25cc3307 (commit)
	from  https://github.com/Gnucash/gnucash/commit/bbcf19ae (commit)



commit 25cc3307228d7ec6f216767f628bf241ae720d1d
Author: Geert Janssens <geert at kobaltwit.be>
Date:   Wed Aug 28 20:55:29 2019 +0200

    797171 - Allow multiple credit/debit columns to be selected
    
    This required some tweaks in the core csv import code
    - first don't unset other deposit/withdrawal columns when selecting a second one
    - amounts have to be summed for all deposit/withdrawal colums
      I have added a new member function 'add' in addition to 'set' and 'reset'
      That function will only work for deposit or withdrawal columns



Summary of changes:
 gnucash/import-export/csv-imp/gnc-imp-props-tx.cpp | 49 ++++++++++++++++++++++
 gnucash/import-export/csv-imp/gnc-imp-props-tx.hpp |  1 +
 gnucash/import-export/csv-imp/gnc-import-tx.cpp    | 44 +++++++++++++------
 3 files changed, 82 insertions(+), 12 deletions(-)