Labels instead of Nav keys in the navigation section option lists

jmlweb

I think it would be more useful if you use the Label of a menu element in the option list for selecting a parent, under the navigation fuel section. Actually, the nav_key is used, but you can have more than one element with the same nav_key

admin

Actually... "nav_key" should probably be a unique value but currently is only unique if it has the same parent. Let me look into that.

admin

I've pushed a change to make nav_keys unique regardless of parent. Labels aren't used because it's possible to have the same label for different menu items.