redesign issue box to look more soft
Merge branch 'issue-box-redesign' into 'master'

Issue box redesign

I complained before about the issue box looks. This is a proposed redesign.

The background of the issue is slightly lighter than the comments, so there is a clear distinction.

To make sure the issue then doesn't disappear, the shadow is slightly strongly (but still barely noticeable, to keep it flat).

The left top corner is round to highlight the status 'label', as it were a real label.

See merge request !1125