fix(datepicker): compatibility with angular 1.1.5 and no jquery

Closes #760

Author: Swiip

src/datepicker/datepicker.js

@@ -290,8 +290,8 @@ function ($compile, $parse, $document, $position, dateFilter, datepickerPopupCon
       ngModel.$parsers.push(parseDate);
 
       var getIsOpen, setIsOpen;
-      if ( attrs.open ) {
-        getIsOpen = $parse(attrs.open);
+      if ( attrs.isOpen ) {
+        getIsOpen = $parse(attrs.isOpen);
         setIsOpen = getIsOpen.assign;
 
         originalScope.$watch(getIsOpen, function updateOpen(value) {
@@ -386,15 +386,22 @@ function ($compile, $parse, $document, $position, dateFilter, datepickerPopupCon
         scope.position.top = scope.position.top + element.prop('offsetHeight');
       }
 
+      var documentBindingInitialized = false, elementFocusInitialized = false;
       scope.$watch('isOpen', function(value) {
         if (value) {
           updatePosition();
           $document.bind('click', documentClickBind);
-          element.unbind('focus', elementFocusBind);
+          if(elementFocusInitialized) {
+            element.unbind('focus', elementFocusBind);
+          }
           element[0].focus();
+          documentBindingInitialized = true;
         } else {
-          $document.unbind('click', documentClickBind);
+          if(documentBindingInitialized) {
+            $document.unbind('click', documentClickBind);
+          }
           element.bind('focus', elementFocusBind);
+          elementFocusInitialized = true;
         }
 
         if ( setIsOpen ) {

src/datepicker/docs/demo.html

@@ -6,7 +6,7 @@
     </div>
 
     <div class="form-horizontal">
-        <input type="text" datepicker-popup="dd-MMMM-yyyy" ng-model="dt" open="opened" min="minDate" max="'2015-06-22'" datepicker-options="dateOptions" date-disabled="disabled(date, mode)" ng-required="true" />
+        <input type="text" datepicker-popup="dd-MMMM-yyyy" ng-model="dt" is-open="opened" min="minDate" max="'2015-06-22'" datepicker-options="dateOptions" date-disabled="disabled(date, mode)" ng-required="true" />
         <button class="btn" ng-click="open()"><i class="icon-calendar"></i></button>
     </div>
 

src/datepicker/test/datepicker.spec.js

@@ -1029,7 +1029,7 @@ describe('datepicker directive', function () {
     describe('toggles programatically by `open` attribute', function () {
       beforeEach(inject(function() {
         $rootScope.open = true;
-        var wrapElement = $compile('<div><input ng-model="date" datepicker-popup open="open"><div>')($rootScope);
+        var wrapElement = $compile('<div><input ng-model="date" datepicker-popup is-open="open"><div>')($rootScope);
         $rootScope.$digest();
         assignElements(wrapElement);
       }));