See merge request nexedi/slapos!1388

See merge request nexedi/slapos!1352

also use same version as stack/slapos.cfg for other eggs.

The official version of manuel has now the fix for which we needed a dev
version.

Pick the latest python2 compatible version.

Rotate every 100MB over enb.xlog, enb.xlog.1, ... enb.xlog.9

Add a service that runs `xamari xlog stats[samples,rf]/<period>s` in
enb/gnb instance. For now the resulting logfile enb.xlog/gnb.xlog is
placed in monitor public folder to be served by monitor http server.

Optionally the service also includes `x.drb_stats/<period>s`, which
implies 100Hz polling. This is enabled by default.