AddressProperty route for /addr/[:addr]/property

eg /addr[:addr]/balance will return just the balance for the address.
This needs expanding but is a good basis upon which to expand.

app/controllers/addressProperties.js

@@ -0,0 +1,34 @@
+'use strict';
+
+/**
+ * Module dependencies.
+ */
+
+var Address = require('../models/Address'),
+    common      = require('./common');
+
+var getAddr = function(req, res, next) {
+  var a;
+  try {
+    var addr = req.param('addr');
+    a = new Address(addr);
+  } catch (e) {
+    common.handleErrors({message: 'Invalid address:' + e.message, code: 1}, res, next);
+    return null;
+  }
+  return a;
+};
+
+
+exports.balance = function(req, res, next) {
+  var a = getAddr(req, res, next);
+  if (a)
+    a.update(function(err) {
+      if (err) {
+        return common.handleErrors(err, res);
+      }
+      else  {
+        return res.jsonp(a.balanceSat);
+      }
+    });
+};

config/routes.js

@@ -32,6 +32,10 @@ module.exports = function(app) {
   app.get(apiPrefix + '/addr/:addr', addresses.show);
   app.get(apiPrefix + '/addr/:addr/utxo', addresses.utxo);
 
+  // Address property routes
+  var addressProperties = require('../app/controllers/addressProperties.js');
+  app.get(apiPrefix + '/addr/:addr/balance', addressProperties.balance);
+
   // Status route
   var st = require('../app/controllers/status');
   app.get(apiPrefix + '/status', st.show);