gnucash maint: Multiple changes pushed

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/40bcd1e3 (commit)
	 via  https://github.com/Gnucash/gnucash/commit/4fe12f54 (commit)
	 via  https://github.com/Gnucash/gnucash/commit/87533fe4 (commit)
	from  https://github.com/Gnucash/gnucash/commit/6d2ef903 (commit)



commit 40bcd1e37779b2c6bcc1fc1cdb00aef8f28adb34
Author: John Ralls <jralls at ceridwen.us>
Date:   Fri Sep 21 14:33:02 2018 -0700

    Bump the max_denom_mult to match the new GNC_COMMODITY_MAX_FRACTION.

commit 4fe12f54225938c9479f17c4f80ebe64762f1b19
Author: John Ralls <jralls at ceridwen.us>
Date:   Fri Sep 21 14:32:03 2018 -0700

    Some more magic number replacements.

commit 87533fe4bcb659ebacec6f50ed68070175d4aeda
Author: John Ralls <jralls at ceridwen.us>
Date:   Fri Sep 21 14:28:49 2018 -0700

    Catch std::underflow_error as well as std::overflow_error.
    
    Any operation that can overflow will throw an underflow if it's a
    negative number. The C interface needs to catch both to prevent
    unhandled exception crashes,



Summary of changes:
 libgnucash/engine/gnc-numeric.cpp                 | 11 +++++++++++
 libgnucash/engine/test-core/test-engine-stuff.cpp |  4 ++--
 libgnucash/engine/test/utest-Split.cpp            |  6 +++---
 3 files changed, 16 insertions(+), 5 deletions(-)