gnucash maint: Multiple changes pushed

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/c1b5e6c8 (commit)
	 via  https://github.com/Gnucash/gnucash/commit/70fe66c9 (commit)
	 via  https://github.com/Gnucash/gnucash/commit/5da9e2f4 (commit)
	from  https://github.com/Gnucash/gnucash/commit/8efc0e7b (commit)



commit c1b5e6c8df22ff680c436e670287de5aee10fe9d
Author: John Ralls <jralls at ceridwen.us>
Date:   Sat Dec 16 15:28:56 2017 -0800

    Release 2.6.19

commit 70fe66c9fd9bbe78234e939a1dde26a0ab696d21
Author: John Ralls <jralls at ceridwen.us>
Date:   Sat Dec 16 15:11:14 2017 -0800

    Fix python tests when building from tarball.

commit 5da9e2f4c98eabf3417afc173c2b0654a0b94e5a
Author: John Ralls <jralls at ceridwen.us>
Date:   Sat Dec 16 11:28:24 2017 -0800

    Update Dutch and Serbian translations from the Translation project.



Summary of changes:
 CMakeLists.txt                           |    2 +-
 ChangeLog                                |  378 +++++-
 NEWS                                     |   22 +
 configure.ac                             |    2 +-
 po/nl.po                                 | 2180 ++++++++++++++++--------------
 po/sr.po                                 |  442 +++---
 src/optional/python-bindings/Makefile.am |   13 +-
 7 files changed, 1769 insertions(+), 1270 deletions(-)