Rendering parameterised menus

Currently the Menu.item builtin snippet does not render menu items created as Menu.param or Menu.params

It would be nice if Lift were able to render such menus using standard menu builders.

A write up exists at

https://groups.google.com/forum/#!topic/liftweb/wrjTCjRLZ1o

and

https://groups.google.com/forum/#!topic/liftweb/w2SECWThckg

Start with the Menu.item builtin snippet and read the two linked Google Groups write-ups for the expected behavior. Trace how Menu.param and Menu.params are handled by standard menu builders, then verify that parameterised menu items render correctly through those builders.

Written by the indexing model from the issue text.