Improve new version handling
This merge request refactors the new version handling API wise.
It now does not guess what the new version should be. The version value shall be send along the rest of the data so the content of the platform can properly be checked.
After this update people shall update to beat/beat.cmdline> version 1.7.1
Related to beat.cmdline#67 (closed)
Fixes #547 (closed)