'stable' is going to become Rock's 'stable' branch on orocos-toolchain

Following a discussion among the Rock and orocos toolchain developers,
we decided to try and share the same repositories, and therefore both
develop on the same 'master' branch. The main reason being that the
tooling part is mainly currently developed in Rock currently, which
causes the orocos toolchain to lag behind, sometimes a lot.

A practical implication would be that the 'stable' branch is going to be
used by Rock from now on. That branch is going to be forced push (i.e.
"reset") to the rock-stable state. It has been considered a minor issue
by the orocos devs, but we would like to:
- make sure that it won't break the setup of current users in bad ways
(speak !)
- make sure that you are aware of the change.

Please speak now if you are a major user of the 'stable' branches and
see a problem with switching to the 'versioned' branches of
orocos-toolchain (e.g. toolchain-2.6)