multi level menus

[tablatronix]

modify get_navigation for multilevel menus.

I also find it bad that we do not output an ol/ul container, or provide the option to.

[tablatronix]

I am trying to figure out what we should do with menu items with broken paths to them.

• Parent [menu]
  • Child 1 [menu]
  • Child 2
    • Child 2 a [menu] <- where does this go

We either remove it, or push it to root like so

• Parent [menu]
  • Child 1 [menu]
• Child 2 a [menu]

We could also find closest parent in menu and add it there but that seems confusing and is a pain in the ass to do also since we wont be caching the parent

This will also cause issues if caching menus, as it makes getting child menus harder or impossible
get_subnav('Child2') wont work if child2 isnt in the cache map

[tablatronix]

Since I cant decide how to handle this, i coded it to be able to do both.

SO it can do this instead

• Parent [menu]
  • Child 1 [menu]
  • Child 2 a [menu]

I think i18n just hides them

• Parent [menu]
  • Child 1 [menu]

[hameau]

This:

• Parent [menu]
  • Child 1 [menu]
  • Child 2 a [menu]

would seem to be the choice of least surprise, imo. It avoids adding to the Parent list (probably the main nav, which may break by wrapping), but remaining visible/accessible.