[feature] XRay version display in the UI

[noiseonwires]

Could you please display somewhere (e.g. in the "About" box) a version of bundled XRay-core? This will be helpful to understand what exactly features are supported.

[InvisibleManVPN]

@uprt By adding #60, you can see application and xray core version in the about window.
To see this feature, wait for the new version of Invisible Man XRay.

Thanks for your feature suggestion!