* configure.in: Test for BROKEN_PY_INITIALIZE feature (before
Python 2.0, Python would write to the environment, and we had to
work around it.)

* acconfig.h: Add BROKEN_PY_INITIALIZE

* plugins/python-loader/python-loader.c (BROKEN_PY_INITIALIZE): Test
for this condition is now autoconfiscated.

* plugins/python/python.c (BROKEN_PY_INITIALIZE): Test for this
condition is now autoconfiscated.  struct FuncData: Include category.
(register_function): Save category.
(plugin_can_deactivate_general): Able to deactivate unless a
function is in use.
(plugin_cleanup_general): Do cleanup.