Refactor JavaScript library.

- Separate classes in separate modules (files)
- Constants should be associated with a class
- Replace exports.config scheme with a config singleton
- Refactor base58 functions as a static class

test/jsonrpc-test.js

@@ -12,8 +12,8 @@ var testutils = require("./testutils.js");
 
 var config = require("./config.js");
 
-require("../src/js/amount.js").config = require("./config.js");
-require("../src/js/remote.js").config = require("./config.js");
+var extend    = require('extend');
+extend(require('../src/js/config'), require('./config'));
 
 // How long to wait for server to start.
 var serverDelay = 1500;