Refactor to fix project build

So it turns out that building the project was also broken by the `require('requirejs')` line in the settings parser. The reason for this is that it was not using the local requireJS dependency of the grunt module (contrary to the nodeJS docs) and some other version on the system (although not the global one, as I puts some logs in that to check).

I could get it to load the local requireJS using an absolute path, but this returned an empty object and after a long rabbit hole, I've decided to ditch requireJS altogether on the nodeJS side for parsing this settings file, as I could find no way to make it work.

The consequence of this is that it needs a change to how we load the `settings.js` file, as we can't load it in via a requireJS call, it needs to be a basic JSON file instead of a  requireJS `define` file.

Hence this PR also two others in edetail-project and edetail-lib:
* https://github.com/incuna/edetail-project/pull/107
* https://github.com/incuna/edetail-lib/pull/114

This also has the benefit of moving a lot of the file path code into the lib/settings.js module, which tidies up the main project gruntfile very nicely.

P.S. Sorry for the many PRs...