Setup welcome page & localization support

Few lines of ruby code, mostly env setup.
@jsyeo Is GitHub issues to be used as the feature tracking tool, or PivotalTracker or something else?

@wangqiang1208 Generally the answer to "Pull Requests for everything?" is "Yes". 

In the industry, we do that all the time, and everyone will try not to push straight to master unless there's a very good reason to do that. Also, by separating the features into smaller PRs, it's easier to review them and to improve/merge them. Hope this explains.