#3 launcher check for updates

[niandrei]

The launcher should check for updates when it is started.
( Add a NaN bug fix when the server can not be reached);
If there are no updates available, then display the "Play game" button;
If there are updates, then download and install, then display the "Play game" button;

[niandrei]

resolved

[niandrei]

this needs to be re-implemented, written in c++ and under irrlicht.