Improve parser error handling

In cases where one side of the connection is not communicated with valid
ASN.1/BER, it would be better to fire an error event rather than let the
exception bubble all the way up.

Fix mcavage/node-ldapjs#142

lib/messages/parser.js

@@ -113,8 +113,14 @@ Parser.prototype.getMessage = function (ber) {
 
   var self = this;
 
+  try {
     var messageID = ber.readInt();
     var type = ber.readSequence();
+  } catch (e) {
+    // Handle servers that aren't speaking the language at all
+    this.emit('error', e);
+    return false;
+  }
 
   var Message;
   switch (type) {