Autofills vomnibar with autocompleted selections

When user moves to an autocompleted selection, its url automatically
populates the textbox. When a user pressed backspace, the selection
is set to -1 (deselected) and the list is repopulated. When the user
manually deselects autocompletions (i.e. moves up to the textbox),
the textbox is cleared
Fixed bug with enter not going where you'd want it to