Add python support to playerstage-player

[apoikos@…]

player has support for generating python bindings to the client libraries. This is done automatically, if swig is present during configure- and compile-time. As python is for many people much more appropriate for rapid prototyping than C or C++, IMHO it makes sense to enable python support by default (by adding python and swig dependencies), or by adding a suitable 'python' variant.

[nox@…]

We should add a python variant and disable the automatic support, as it would enable it if swig and python25 are installed, even if the user didn't enable python variant.

[vincent@…]

Included in the new version see ticket #15932

[ryandesign@…]

The python variant in #15932 does not satisfy the request expressed by Anthony above. No attempt has been made to disable python support by default, and to only enable it if the python variant is selected.