Support a structure for countries with multiple gov't levels #212

[Abbe98]

This allows contributors to split a country into an unlimited(not really tested beyond two) set of levels. The United Kingdom is provided as an example but others should maybe be split as well(Russia?).

Known end-user issues:

• The lower level pages render in the wrong location because / in their rendering path is replaced with _.
• The "Federal subjects" title is rendered on a different level than the details icon
• The map "list" renders all levels not only the top one
• The country list includes both countries and any lower levels
• Even if you are on a third level the title will say "Federal subjects" (if this ever becomes an issue lets find a more generic title)
• The statistics page shows all levels (maybe a feature?)
• The statistics page's country counter is affected by non-top levels
• The lower levels lack a button to navigate to the top level

Implementation issues:

• the federal subjects are not defined in countries.rq which would make a lot more of sense
• The "Scotland|scotland,Wales|wales" syntax for defining subjects aren't very nice
• ge (len (split $m.safeName "/")) 2 is a rather horrifying hack to write a contains function

[Ainali]

I added a commit with styling for the "Federal subjects". Now, it won't be an H2, but I think that can be okay anyway.

[Abbe98]

You will now need Snowman 0.6.0 to build this branch: https://github.com/glaciers-in-archives/snowman/releases/tag/0.6.0

[Abbe98]

I'm quite happy with the implementation now and think that the remaining issues can wait. Updated documentation aside.

[Ainali]

I'm quite happy with the implementation now and think that the remaining issues can wait. Updated documentation aside.

Yes, I too think this is good enough to start with. We could convert the outstanding checkboxes to individual issues to not forget them.