Catching uncatchables

We were having trouble with spec errors in EventListeners. For example, spec errors thrown when handling the response to an ajax request were uncaught and printed badly.

There are Closure Library functions which can help with these cases. Possibly of use for cljs-devtools

```
(ns condense.preload
(:require [goog.debug.entryPointRegistry :as gepr])
(:import [goog.debug ErrorHandler]))

(defn handle-error [e]
(js/console.debug (.-stack e))
(js/console.debug (ex-data e)))

(def error-handler (doto (ErrorHandler. handle-error)
(.protectWindowSetTimeout)
(.protectWindowSetInterval)
(.protectWindowRequestAnimationFrame)))

(gepr/monitorAll error-handler)
```

首先跟踪 EventListeners 如何处理来自异步 Ajax 响应的规范错误，然后将该路径与 Issue 中的 Closure Library ErrorHandler 和 entryPointRegistry 示例进行比较。完成的标准是捕获这些错误，并通过有用的 stack 和 ex-data 输出进行报告；由于没有指定源文件或测试，因此必须先定位相关的集成点。

由索引模型根据 Issue 内容生成。