Address nits

Author: jasnell

doc/api/events.markdown

@@ -427,7 +427,7 @@ Returns a reference to the `EventEmitter` so calls can be chained.
 * `listener` {Function} The callback function
 
 Adds a **one time** `listener` function for the event named `eventName` to the
-beginning of the listeners array. This listener is invoked only the next time 
+*beginning* of the listeners array. This listener is invoked only the next time
 `eventName` is triggered, after which it is removed.
 
 ```js

lib/_stream_readable.js

@@ -12,10 +12,10 @@ var StringDecoder;
 
 util.inherits(Readable, Stream);
 
-const has_firston = typeof EE.prototype.prependListener === 'function';
+const hasPrependListener = typeof EE.prototype.prependListener === 'function';
 
 function prependListener(emitter, event, fn) {
-  if (has_firston)
+  if (hasPrependListener)
     return emitter.prependListener(event, fn);
 
   // This is a brutally ugly hack to make sure that our error handler