HTML Generation: ONE root <ul> with hierarchical children rather than current MULTIPLE <ul> roots.

Issue Summary

+ I like that your module works both with and without Javascript.
- What I like less, is the HTML list structure it generates.

The way i.e. Superfish and also most other websites (regardless which CMS backend) implement hierarchical menus: One root list with hierarchical children. That is <ul> with <li> children, which are again a parent to an <ul> if they contain subitems, and so on. You on the contrary create one root <div> and every child is a <ul>, which then again has the <li> ... <ul> ... <li> children.

In other words: Instead of creating one tree with all its multiple branches, you create multiple trees with again their multiple branches.

If you view a Dynamic Persistent Menu enabled site through the text browser Lynx, the structural disadvantage gets obvious immediately. Text browsers, web search bots can still find and follow all the menu links, but their hierarchical (and hence semantical) meaning is lost! This may be a SEO disadvantage.

I hence propose to you that you change to the ONE tree MULTIPLE branches HTML approach.

See the illustrations below and note, that I am using Special Menu Items, which allows placeholder (= non clickable) and separator menu items. In my example those placeholders are denoted by using quotes arround them.