Replace .has_key for python bindings
Replace .has_key for python bindings

dict.has_key is only available in python2.x, the `key in dict` syntax is
available in python2.3 and later. This should allow the python bindings
to work for more versions.

JoshChristie/displaz,JoshChristie/displaz,JoshChristie/displaz,JoshChristie/displaz,JoshChristie/displaz