Add version information during build task

This PR adds the version string (simplest implementation) during the build phase to the dist version to be called via $translate.versionInfo() afterwards.
Provides an alternative approach to #464 - as discussed in that ticket.

See also #404.

@tspaeth I'm okay with `x.y.z` here unless you have something different that is `abstract` too. I would also be okay with `0.0.0` but I like `x.y.z` more.