Add minimumCompatibleVersion and update refresh modal to show more detail informations

lib/config.js

@@ -78,11 +78,13 @@ function getserverurl() {
 }
 
 var version = '0.4.2';
+var minimumCompatibleVersion = '0.4.2';
 var maintenance = true;
 var cwd = path.join(__dirname, '..');
 
 module.exports = {
     version: version,
+    minimumCompatibleVersion: minimumCompatibleVersion,
     maintenance: maintenance,
     debug: debug,
     urlpath: urlpath,

lib/realtime.js

@@ -708,7 +708,10 @@ function connection(socket) {
 
     //check version
     socket.on('version', function () {
-        socket.emit('version', config.version);
+        socket.emit('version', {
+            version: config.version,
+            minimumCompatibleVersion: config.minimumCompatibleVersion
+        });
     });
 
     //received cursor focus