Remove keyring from openpgp namespace. Optimize keyid initialization.

src/index.js

@@ -1,7 +1,6 @@
 
 module.exports = require('./openpgp.js');
 module.exports.key = require('./key.js');
-module.exports.keyring = require('./keyring.js');
 module.exports.message = require('./message.js');
 module.exports.util = require('./util');
 module.exports.packet = require('./packet');

src/type/keyid.js

@@ -27,11 +27,15 @@ var util = require('../util');
  */
 module.exports = function keyid() {
 
-  this.bytes = '';
-
+  // initialize keyid with 0x0000000000000000
+  var strArray = [];
+  var zero = String.fromCharCode(0);
   for (var i = 0; i < 8; i++) {
-    this.bytes += String.fromCharCode(0);
+    strArray[i] = zero;
   }
+  this.bytes = strArray.join('');
+
+
   /**
    * Parsing method for a key id
    * @param {String} input Input to read the key id from 

test/crypto/openpgp.sigcheck.js

@@ -2,7 +2,7 @@ var unit = require('../unit.js');
 
 unit.register("Testing of binary signature checking", function() {
   var openpgp = require('../../');
-  var keyring = openpgp.keyring;
+  var keyring = require('../../src/keyring.js');
   var result = [];
   var priv_key = openpgp.key.readArmored([
         '-----BEGIN PGP PRIVATE KEY BLOCK-----',

test/general/openpgp.basic.js

@@ -2,7 +2,6 @@ var unit = require('../unit.js');
 
 unit.register("Key generation/encryption/decryption", function() {
   var openpgp = require('../../');
-  var keyring = openpgp.keyring;
   var result = [];
   var testHelper = function(passphrase, userid, message) {
     var key = openpgp.generateKeyPair(openpgp.enums.publicKey.rsa_encrypt_sign, 512,