Fix for keyboard controls
Fix for keyboard controls

Previously we used addEventlisteners, but with the introduction of the ng-if of the list we couldn't use those any more so now we use ng-keydown instead (this is also cleaner)

dotansimha/angularjs-dropdown-multiselect,dotansimha/angularjs-dropdown-multiselect,gertot/angularjs-dropdown-multiselect,gertot/angularjs-dropdown-multiselect,jjwon0/angularjs-dropdown-multiselect,jjwon0/angularjs-dropdown-multiselect