Added config option enterIsCancelled (boolean). When true the default action of the enter key (when no list is shown) is prevented.
Added config option enterIsCancelled (boolean). When true the default
action of the enter key (when no list is shown) is prevented.

Change-Id: I3961d1e211a694fcc3eb58e8489947478b5dc93a

Vectrex/vxJS