Report errors to developer consoles, not users

In #224 we had a brief discussion which concluded that these statements about error reporting really referred to a developer console. Alternately, maybe they are holdovers from the early days of the web when browsers did in fact show popups with every JavaScript error. Regardless, this uniformly updates all script error reporting to be to a developer console, instead of to the user.

source

@@ -86275,8 +86275,8 @@ interface <dfn>NavigatorOnLine</dfn> {
   data-x="concept-script">script</span>, with the problematic position (line number and column
   number) in the resource containing the script, using the <span>global object</span> specified by
   the script's <span>settings object</span> as the target. If the error is still <i
-  data-x="concept-error-nothandled">not handled</i> after this, then the error may be reported to
-  the user.</p>
+  data-x="concept-error-nothandled">not handled</i> after this, then the error may be reported to a
+  developer console.</p>
 
 
   <h6>The <code>ErrorEvent</code> interface</h6>
@@ -87323,7 +87323,7 @@ typedef <span>OnBeforeUnloadEventHandlerNonNull</span>? <dfn>OnBeforeUnloadEvent
        column number) given by <var>location</var>, using the <span>global object</span>
        specified by <var>script settings</var> as the target. If the error is still <i
        data-x="concept-error-nothandled">not handled</i> after this, then the error may be reported
-       to the user.</p></li>
+       to a developer console.</p></li>
 
        <li><p>Return null.</p></li>
 
@@ -95162,7 +95162,7 @@ interface <dfn>WorkerGlobalScope</dfn> : <span>EventTarget</span> {
   the target.</p>
 
   <p>For shared workers, if the error is still <i data-x="concept-error-nothandled">not handled</i>
-  afterwards, the error may be reported to the user.</p>
+  afterwards, the error may be reported to a developer console.</p>
 
   <p>For dedicated workers, if the error is still <i data-x="concept-error-nothandled">not
   handled</i> afterwards, the user agent must <span>queue a task</span> to <span