[Bf-vfx] Improving the 2D stabilization tool :: documentation

[Ichthyostega]

Hello all,

as you'll probably noticed, the reworked 2D stabilizer code is part of the
upcoming release. This necessitates to update the relevant documentation,
and maybe expand it a bit with some explanations.

Now I'm done with a daft version of the text and some additional example
images; the idea is to have a dedicated page "2D Stabilization", which allows
to keep the documentation in the "video clip properties" page rather terse and
at the bare minimum. We'd link from there to the new dedicated page then.

Now since I am deeply engaged in the technical details, it is challenging for me
to write documentation from a users point of view. Thus I'd be glad to get some
feedback, critique, proposals...

The main page, which is intended for the user manual, is drafted here:
https://wiki.blender.org/index.php/User:Ichthyostega/docs/2DStabilization


Besides that, there is also an entry for the release notes:
https://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.78/More_Features#2D_Stabilization


-- Hermann


PS: I am aware that the next step in the release process is to submit
a patch against the actual user manual source tree