gnucash unstable: Fix read and write of business counters and counter_formats

[Geert Janssens]

Updated	 via  https://github.com/Gnucash/gnucash/commit/4053f2ca (commit)
	from  https://github.com/Gnucash/gnucash/commit/d6a5cc9f (commit)



commit 4053f2ca5331b345f04f75022658d254c36bdd15
Author: Geert Janssens <geert at kobaltwit.be>
Date:   Sat Mar 31 18:27:43 2018 +0200

    Fix read and write of business counters and counter_formats
    
    These are book options, but not stored under the default options frame (sigh)
    So add exception code to properly access them.



Summary of changes:
 libgnucash/engine/qofbook.cpp | 52 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 39 insertions(+), 13 deletions(-)