Add config file API

src/app.js

@@ -11,6 +11,7 @@ var GistHandler = require('./app/gist-handler')
 var gistHandler = new GistHandler()
 
 var Storage = require('./app/storage')
+var Config = require('./app/config')
 var Editor = require('./app/editor')
 var Renderer = require('./app/renderer')
 var Compiler = require('./app/compiler')
@@ -40,6 +41,7 @@ var run = function () {
   var self = this
   this.event = new EventManager()
   var storage = new Storage()
+  var config = new Config(storage)
 
   function loadFiles (files) {
     for (var f in files) {

src/app/config.js

+'use strict'
+
+var CONFIG_FILE = '.browser-solidity.json'
+
+function Config (storage) {
+  this.items = {}
+
+  // load on instantiation
+  var config = storage.get(CONFIG_FILE)
+  if (config) {
+    this.items = JSON.parse(config)
+  }
+
+  this.exists = function (key) {
+    return this.items[key] !== undefined
+  }
+
+  this.get = function (key) {
+    return this.items[key]
+  }
+
+  this.set = function (key, content) {
+    this.items[key] = content
+    storage.set(CONFIG_FILE, JSON.stringify(this.items))
+  }
+}
+
+module.exports = Config