[GNC] gncJobNextID in gncJob.c not in gncJob.h

[Robert Simmons]

> we should consider changing the license to GPL-Affero to preclude someone
using GnuCash in a non-Free software-as-a-service scheme

That is a consideration. When I hit the point of needing to write quite a
lot of code to get GnuCash to do exactly what I want, I looked into other
projects. I took a look at Akaunting which seems to solve the API
issues I'm having. The problem with that one is the install process is a
bit annoying. I noticed that they use GPL 3, not AGPL too which is
interesting.

https://github.com/akaunting/akaunting/blob/master/LICENSE.txt