connection: close connection on transport error

This commit forces a connection to close if a transport emits error.
Socket-related errors should have been already doing this, but parse
errors just emitted error events that caused the invalid chunk to be
parsed over and over again if the event was intercepted.

Refs: #76
PR-URL: #78

lib/connection.js

@@ -309,6 +309,7 @@ Connection.prototype._onSocketClose = function() {
 //   error - error that has occured
 //
 Connection.prototype._onSocketError = function(error) {
+  this._end();
   this.emit('error', error, this);
 };