gnucash master: Multiple changes pushed

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/b5afd2e3 (commit)
	 via  https://github.com/Gnucash/gnucash/commit/5e41c79c (commit)
	from  https://github.com/Gnucash/gnucash/commit/75073a7a (commit)



commit b5afd2e319b0f06697c83806e85dd15fab508e5b
Author: John Ralls <jralls at ceridwen.us>
Date:   Fri Oct 4 12:26:35 2019 -0700

    Set C and C++ standards the modern Cmake way, and set C++ to C++17.
    
    Boost has to go to 1.67 as well because boost::locale used auto_ptr
    before that and it's been removed from the language in C++17.

commit 5e41c79c7697a22c37c20fe3e51606966d81d712
Author: John Ralls <jralls at ceridwen.us>
Date:   Fri Oct 4 12:07:15 2019 -0700

    Require SWIG >=3.0.12 for facility to extend C++ classes with templates.



Summary of changes:
 CMakeLists.txt      | 27 ++++++++++-----------------
 README.dependencies |  8 +++++---
 2 files changed, 15 insertions(+), 20 deletions(-)