Osmium only works with Xenon 1.0.0

[blootsvoets]

Due to the Maven build system and the fact that Xenon only published version 1.0.0, it doesn't work with newer or development versions of Xenon. See also xenon-middleware/xenon#233.

[blootsvoets]

Created a gradle branch, in which it is easy to add xenon to the lib/ directory while in development. It can be used as a replacement of most functions of Maven, unfortunately except maven site.