Added in the ability to delete multiple users at one go
Added in a page to add new users.

* Some modifications were made to the page listing all the users to
  reflect the fact that China is divided into multiple regions.
Added in basic writing to CSV support.
Completed export to CSV file function.

GWT has no native support for file I/O. The download functionality
is handled by a simple HttpServlet that serves up the file upon
request. The download is triggered by a setting the URL of a hidden
iframe __gwt_downloadFrame to make the UX as smooth as possible.
Merge pull request #1 from Ayrx/master

Add // Delete // Export to CSV