供内部调用函数
function backdropIndex() 获取map结构上绑定backdrop的索引
function removeModalWindow(modalInstance, elementToReceiveFocus) //移除模态window
function toggleTopWindowClass() //触发、消除class效果
function checkRemoveBackdrop()检查背景是否不再需要，如不需要调用移除动画
function removeAfterAnimate(domEl, scope, done) 元素domel在scope下动画完成后done()回调
供外部调用函数
$modalStack.open = function(modalInstance, modal){ } //创建一个模态实例，并传入modal里的参数
$modalStack.close = function(modalInstance, result){}//modalStack的关闭模态函数
$modalStack.dismiss = function(modalInstance, reason){} 解除模态函数
$modalStack.dismissAll = function(reason){}解除所有
$modalStack.getTop = function() {} //返回openedWindows的顶栈
$modalStack.modalRendered = function(modalInstance) {//模态框渲染
$modalStack.focusFirstFocusableElement = function(){}//获取第一个元素焦点
$modalStack.focusLastFocusableElement = function() {}//获取最后一元素焦点
$modalStack.isFocusInFirstItem = function(evt) {}//判断第一个元素是否处于焦点状态
$modalStack.isFocusInLastItem = function(evt) {} //判断最后一个元素是否处于焦点状态
$modalStack.clearFocusListCache = function() {}//清空焦点列表缓存
$modalStack.loadFocusElementList = function(modalWindow) {}//执行焦点
