[horde] horde/Service_Vimeo temporarily deprecated

[Ralf Lang]

Hello,

I am going to temporarily mark horde/Service_Vimeo as temporarily
deprecated. During my efforts to technically modernize other Service_*
libraries it turned out the Vimeo library is targeting a version of the API
no longer available. While supporting a thoroughly outdated version of an
open source protocol such as KOLAB might have some merit, the Vimeo API in
the version we implement is dead and I don't know of anybody who needs the
newer Vimeo V3.4 API.

At least for now, modernizing Vimeo package is a project for somebody else.
I will rather take care of work we actually benefit from.