Dynamically draw the current version to the splash screen

Dynamically draw the current version to the splash screen. See: http://insights.sigasi.com/tech/how-add-decorator-splash-screen-your-rcp-application.html.

(We may add the build version in a small font in a corner of the splash to help debugging)

(from redmine: issue id 2030, created on 2017/02/10 by Sebastien Jacquot)