Find a way to link Manfest.xml versionName with versionString in splash screen

[pslh]

We display a version string in the splash screen and must also provide a versionName in the Manifest.
Every time we release we are obliged to update both files - it would be preferable to only need to update one (Manifest, since we also need to update versionCode there)

See also:
http://stackoverflow.com/questions/4471025/how-can-you-get-the-manifest-version-number-from-the-apps-layout-xml-variable