Maturity level two issues

[pietersap]

This addresses issues

• 1. 101
• 2. 100
• 3. 95
• 4. 94
• 5. 90

and also the other smaller remarks (see previous merge) by @fgheysels for which there are no seperate issues.

Note: The commits below also includes commits that were already in the previous merge request. I should have kept the commit tree cleaner.

[fgheysels]

I haven't checked yet, but I 'd prefer to have multiple but smaller PR's (for instance one per issue)

[pietersap]

Agreed. I will do this from now, but there were no issues created at the time and many modifications are very small like removing whitespace etc :)

[pietersap]

I'd suggest to first merge this one, before merging any others smaller merge requests that I add in the future.

[MassimoC]

We already have a first global PR, now I want small PRs with clear title, clear description and link to issue.

[pietersap]

@MassimoC Could we still merge this one as a whole? It addresses a lot of smaller remarks by @fgheysels for which there is no issue. Splitting it up now would make it very messy.

[pietersap]

I referenced the related issues.

[MassimoC]

@MassimoC Could we still merge this one as a whole? It addresses a lot of smaller remarks by @fgheysels for which there is no issue. Splitting it up now would make it very messy.

we won't split up :) We will merge as soon reviewed

[MassimoC]

We are normally returning problem+json for all the 4XX and 5XX.