Revert "Easier closing of dialogs" (introduces regression on date time picker)

This reverts commit 71630aaa77.

assets/js/core/modal.js

@@ -1,42 +1,18 @@
 (function () {
     var isOpen = false;
-    var isFormDirty = false;
-
-    function closeIfDirty() {
-        if (isFormDirty == false) {
-            return true;
-        }
-
-        return window.confirm($("body").data("js-modal-close-msg").replace(/\\n/g,"\n"));
-    }
 
     function onOverlayClick(e) {
         if (e.target.matches('#modal-overlay')) {
-            if (closeIfDirty()) {
-                e.stopPropagation();
-                e.preventDefault();
-                destroy();
-            }
+            e.stopPropagation();
+            e.preventDefault();
+            destroy();
         }
     }
 
-    function onBeforeUnload(e) {
-        // Cancel the event as stated by the standard.
-        e.preventDefault();
-
-        // Chrome requires returnValue to be set.
-        e.returnValue = '';
-    }
-
     function onCloseButtonClick() {
         KB.trigger('modal.close');
     }
 
-    function onFormChange() {
-        isFormDirty = true;
-        window.addEventListener('beforeunload', onBeforeUnload, false);
-    }
-
     function onFormSubmit() {
         KB.trigger('modal.loading');
         submitForm();
@@ -75,7 +51,6 @@
     function afterRendering() {
         var formElement = KB.find('#modal-content form');
         if (formElement) {
-            formElement.on('change', onFormChange, false);
             formElement.on('submit', onFormSubmit, false);
         }
 
@@ -90,13 +65,6 @@
         _KB.tagAutoComplete();
         _KB.get('Task').onPopoverOpened();
 
-        if (formElement) {
-            $('.form-date').datepicker('option', 'onSelect', onFormChange);
-            $('.form-datetime').datepicker('option', 'onSelect', onFormChange);
-            $(".color-picker").on('change', onFormChange);
-            $(".tag-autocomplete").on('change', onFormChange);
-        }
-
         KB.trigger('modal.afterRender');
     }
 
@@ -154,8 +122,6 @@
 
     function destroy() {
         isOpen = false;
-        isFormDirty = false;
-        window.removeEventListener('beforeunload', onBeforeUnload, false);
         var overlayElement = KB.find('#modal-overlay');
 
         if (overlayElement) {