python version mismatch

Binary package hint: labyrinth

The file at /usr/bin/labyrinth has a "#!" line with "/usr/bin/env python", which means it will use the default version of python installed. However, it goes on to insert on sys.path the path to the labyrinth package installed in a specific python version. This breaks labyrinth 0.4.0 on Karmic, where the specific python version is 2.5, which is not installed by default.

The attached patch replaces the static python directory insertion with one calculated from the import of the labyrinth python package. It will happen to be the same as the statically included directory if the python versions match.

The attached patch also removes an unnecessary exists() check, since os.path.isdir() implies os.path.exists()