new kubuntu_STABLE branches \o/

[Harald Sitter]

おはようございます

As of right now all repositories in our plasma/ repositories [1] have
a *kubuntu_stable* branch that is (supposed to be) integrating the
upstream Plasma/5.2 branches, respectively whatever is considered the
stable branch by upstream.

N.B.:
This makes things potentially more complicated for us when working
with these repos. Iff you happen to be fixing a stable CI job you must
now do this in the kubuntu_stable branch *not* the unstable one. Also
generally when fixing failing jobs you'd want to start with stable
branches because changes there will also trigger auto-merge into
unstable.

That being said, merger order now looks like this (stable is new
primary merge target of release branches and unstable is the primary
merge target of stable)

master     kubuntu_vivid_archive
   ↓                         ↓
      kubuntu_stable (if existing)
                 ↓
     kubuntu_unstable

[1] http://anonscm.debian.org/cgit/?q=pkg-kde/plasma