gnucash maint: Multiple changes pushed

[Christopher Lam]

Updated	 via  https://github.com/Gnucash/gnucash/commit/b67bf4b7 (commit)
	 via  https://github.com/Gnucash/gnucash/commit/3be79359 (commit)
	from  https://github.com/Gnucash/gnucash/commit/3676728d (commit)



commit b67bf4b761b3d73c32c3e6662c6626e30ff5e2cb
Author: Christopher Lam <christopher.lck at gmail.com>
Date:   Sun Nov 22 21:21:58 2020 +0800

    [c-interface] deprecate gnc:make-string-database

commit 3be79359651eea57d417d57eaec97976f0b3fbbe
Author: Christopher Lam <christopher.lck at gmail.com>
Date:   Sat Nov 21 00:09:59 2020 +0800

    [date-utilities] Convert reldate list into srfi-9 records



Summary of changes:
 libgnucash/app-utils/c-interface.scm    |   2 +
 libgnucash/app-utils/date-utilities.scm | 508 ++++++++++----------------------
 2 files changed, 162 insertions(+), 348 deletions(-)