[WIN] Enabling Visual Styles, so that tooltips can show up. Fix #72.

Enabling Visual Styles, so that tooltips can show up when hover. Fix #72.

For more details: http://msdn.microsoft.com/en-us/library/windows/desktop/bb773175%28v=vs.85%29.aspx

Thanks the help from chromium-dev: [Link](https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/_ztNZjLZCjs%5B1-25-false%5D)