fix(tooltip): fix binding to multiple triggers

- Due to switch to raw `addEventListener`, changed to add and remove
  listeners to event triggers by iteration

Fixes #4371
Closes #4384

src/tooltip/test/tooltip.spec.js

@@ -844,7 +844,7 @@ describe('$tooltipProvider', function() {
 
     describe('triggers with a custom mapped value', function() {
       beforeEach(module('ui.bootstrap.tooltip', function($tooltipProvider) {
-        $tooltipProvider.setTriggers({ 'customOpenTrigger': 'customCloseTrigger' });
+        $tooltipProvider.setTriggers({ customOpenTrigger: 'foo bar' });
         $tooltipProvider.options({trigger: 'customOpenTrigger'});
       }));
 
@@ -866,7 +866,11 @@ describe('$tooltipProvider', function() {
         expect(tooltipScope.isOpen).toBeFalsy();
         trigger(elm, 'customOpenTrigger');
         expect(tooltipScope.isOpen).toBeTruthy();
-        trigger(elm, 'customCloseTrigger');
+        trigger(elm, 'foo');
+        expect(tooltipScope.isOpen).toBeFalsy();
+        trigger(elm, 'customOpenTrigger');
+        expect(tooltipScope.isOpen).toBeTruthy();
+        trigger(elm, 'bar');
         expect(tooltipScope.isOpen).toBeFalsy();
       }));
     });

src/tooltip/tooltip.js

@@ -390,7 +390,9 @@ angular.module('ui.bootstrap.tooltip', ['ui.bootstrap.position'])
                 element.unbind(trigger, showTooltipBind);
               });
               triggers.hide.forEach(function(trigger) {
-                element.unbind(trigger, hideTooltipBind);
+                trigger.split(' ').forEach(function(hideTrigger) {
+                  element[0].removeEventListener(hideTrigger, hideTooltipBind);
+                });
               });
             };
 
@@ -407,7 +409,9 @@ angular.module('ui.bootstrap.tooltip', ['ui.bootstrap.position'])
                     element[0].addEventListener(trigger, toggleTooltipBind);
                   } else if (trigger) {
                     element[0].addEventListener(trigger, showTooltipBind);
-                    element[0].addEventListener(triggers.hide[idx], hideTooltipBind);
+                    triggers.hide[idx].split(' ').forEach(function(trigger) {
+                      element[0].addEventListener(trigger, hideTooltipBind);
+                    });
                   }
                 });
               }