[Rock-dev] Update to master/next/stable

[Sylvain Joyeux]

> (and that the so-called "release manager" does not have the mean to decide what qualifies as "stable").

Since this sentence seem to have been taken as a personal attack --
which I really did not intend -- here's an explanation:
 - a better word for "so-called" here would have been "ill-defined".
The role and power(s) of the person doing the release has never been
defined in the same way than other roles have been defined during the
github migration
(http://rock.opendfki.de/wiki/WikiStart/Standards/RG9). Which is part
of "defining how we do the release".
 - I did not mean to single out anybody in this sentence. When I did
the releases, I did not have the means to decide what qualified as
stable. Nobody does for something decentralized. Even limiting
ourselves to rock.core, the only people that can decide are the ones
that are taking care of the subsystems. One should defer to Alex when
Orocos::Async or Vizkit are concerned (or, more recently, telemetry).
To Matthias when orogen_metadata was. Even seemingly working code
might not be deemed release-ready by the developers, and they are the
ones that will have to maintain it.

Sylvain