We need both a slice name and a prefix for application units. For
consistency we tried to use the same name and ended up standardising on
"apps.slice" and and "apps-" prefix for the units.
However, "app-" would be a more natural prefix for applications. And it
is no problem to simply also name the slice "app.slice" for consistency
rather than keeping the current "apps.slice".
This is work in progress and not finished yet. However, I hope to have
captured some of the key points that came up in previous discussions
with appropriate notes about things that still need to be defined.
I may revisit it later. Also, feel free to completely rewrite if the
format is not quite right.